Full text of "Tektronix Manual: 11801"

See other formats

Service Manual

Tektronix

11801C

Digital Sampling Oscilloscope
070-9972-02

Warning

The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to all safety summaries prior to
performing service.

C€

Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.

Printed in the U.S. A.

Tektronix, Inc., RO. Box 1000, Wilsonville, OR 97070-1000
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

WARRANTY

Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1 ) year from the
date of shipment. If any such product proves defective during this warranty period, Tektronix, at its option, either will repair the
defective product without charge for parts and labor, or will provide a replacement in exchange for the defective product.

In order to obtain service under this warranty. Customer must notify Tektronix of the defect before the expiration of the warranty
period and make suitable arrangements for the performance of service. Customer shall be responsible for packaging and
shipping the defective product to the service center designated by Tektronix, with shipping charges prepaid. Tektronix shall
pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service
center is located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any other charges for
products returned to any other locations.

This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate maintenance
and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting from attempts by
personnel other than Tektronix representatives to install, repair or service the product; b) to repair damage resulting from
improper use or connection to incompatible equipment; or c) to service a product that has been modified or integrated with
other products when the effect of such modification or integration increases the time or difficulty of servicing the product.

THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY OTHER
WARRANTIES, EXPRESSED OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX’ RESPONSIBILITY TO REPAIR OR
REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR
BREACH OF THIS WARRANTY. TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

EC Declaration of Conformity

Tektronix Holland N.V.

Marktweg 73 A
8444 AB Heerenveen
The Netherlands

declare under sole responsibility that the

11801C Digital Sampling Oscilloscope

meets the intent of Directive 89/336/EEC for Electromagnetic Compatihility and Eow
Voltage Directive 73/23/ECC for Product Safety. Compliance was demonstrated to the
following specifications as listed in the Official Journal of the European Communities:

EMC Directive 89/336/EEC:

EN 55011 Class A Radiated and Conducted Emissions

EN 50082-1 Immunity:

lEC 801-2 Electrostatic Discharge Immunity

lEC 801-3 RE Electromagnetic Eield Immunity

lEC 801-4 Electrical East Transient/Burst Immunity
lEC 801-5 Power Eine Surge Immunity

Eow Voltage Directive 73/23/EEC:

EN 61010-1 Safety requirements for electrical equipment for

measurement, control, and laboratory use

Tektronix, Inc. claims compliance to the EMC Directive 89/336/EEC for the following
products when they are used with the above named product:

SD-20

SD-22

SD-24

SD-26

SD-30

SD-32

SD-42

SD-46

SD-51

Declaration of Conformity
with Electromagnetic Compatibility Standards
as Required under the Radiocommunications Act

Tektronix, Inc.
of

Tektronix Australia Pty Limited
80 Waterloo Road
North Ryde NSW 2113

Supplier Code: N60

declare under sole responsibility that the

11801C Digital Sampling Oscilloscope
to which this declaration relates is in conformity with the following standards:

AS/NZS 2064.1/2 Industrial, Scientific, and Medical Equipment: 1992

Tektronix, Inc. claims conformity to the standards for the following products when they
are used with the above named product:

SD-20

SD-22

SD-24

SD-26

SD-30

SD-32

SD-42

SD-46

SD-51

Contacting Tektronix

Product

Support

Service

Support

For other
information

To write us

For application-oriented questions about a Tektronix measurement
product, call toll free in North America:

1-800-TEK-WIDE (1-800-835-9433 ext. 2400)

6:00 a.m. - 5:00 p.m. Pacific time

Or, contact us by e-mail:
tm_app_supp@tek.com

For product support outside of North America, contact your local
Tektronix distributor or sales office.

Contact your local Tektronix distributor or sales office. Or, visit our web
site for a listing of worldwide service locations.

http://www.tek.com

In North America:

1-800-TEK-WIDE (1-800-835-9433)

An operator will direct your call.

Tektronix, Inc.

RO. Box 1000

Wilsonville, OR 97070-1000

11801C Service Manual

Contacting Tektronix

Table of Contents

Contacting Tektronix i

Generai Safety Summary xvii

Service Safety Summary xix

Specifications

Operating information

Sampling Head Installation and Removal 2-2

Power Information 2-4

Power Cord Information 2-5

Memory Backup Power 2-6

Operating Environment 2-6

Operating Temperature 2-6

Ventilation Requirements 2-6

Packaging for Shipment 2-7

Theory of Operation

System Functional Overview 3-3

Acquisition System Block 3-3

Strobe Distribution Block 3-3

Time Base/Controller Block 3-3

Trigger Select Block 3-3

Executive Processor Block 3-4

Memory Management Unit Block 3-4

Waveform Memory Block 3-4

Front Panel Controls 3-5

I/O Block 3-5

Waveform Compressor and Display Control Block 3-5

Power Supply 3-6

Typical Waveform Processing Cycle 3-6

11801C Service Manual

Table of Contents

Block Diagram Descriptions 3-7

A1 M/F Strobe Drive Board 3-7

Data Buffers 3-7

Address Latch 3-7

Function Decoder 3-7

Internal Clock Rate Generator 3-7

Control Buffer 3-8

A3 M/F Power Connect Board 3-8

A4 Regulator Board 3-8

Voltage Fault Detect 3-8

A5 Time Base/Controiier Board 3-9

Microprocessor 3-9

RAM/ROM Memory 3-9

Trigger 3-9

Time Base 3-11

Acquisition System Interface 3-11

Memory Management (MMU) Interface 3-11

A7 CRT Socket Board 3-12

Red, Green, and Blue Video Amplifiers 3-12

Red, Green, and Blue Adjustments 3-12

Convergence Adjustment 3-12

A8 CRT Driver Board 3-13

Horizontal Sweep 3-13

Vertical Sweep 3-13

High Voltage and Grid Voltage Generator 3-13

Degauss 3-14

Beam Current Limit 3-14

Grid Bias 3-14

A9, A10, and All Front Panel Boards 3-14

Touch Panel, Major Menu Keys, and Menu Status LEDs .... 3-14

A9 Touch Panel Assembly 3-14

A10 Front Panel Control Board 3-15

A1 1 Front Panel Button Board 3-15

A12 Rear Panel Assembly 3-15

GPIB Data and Address Bus 3-16

Standard RS-232-C Controller 3-16

PrinterPort 3-17

A1 3 Mother Board 3-17

A1 4 Input/Output (I/O) Board 3-18

I/O Data Buffer 3-18

I/O Delayed Data Buffer 3-18

Timer Configuration 3-19

Real Time Clock 3-19

Serial Data Interface (SDI) 3-19

Tone Generator 3-19

Temp/Tone Readback Buffer 3-19

Contents

Table of Contents

A15 Memory Management (MMU) Board 3-20

MMU IC 3-20

Waveform RAM 3-20

Display Interface 3-20

Time Base/Controller Interface 3-21

Executive Processor (EXP) Interface 3-21

Display IC 3-21

Microprocessor 3-21

Bit Map RAM 3-21

Waveform Display RAM 3-22

Video Digital-to-Analog Convertor (DAC) 3-22

A1 7 Executive Processor Board 3-22

Executive Processor (EXP) 3-22

Numeric Coprocessor 3-23

Bus Controller 3-23

Reset 3-23

Wait State 3-23

Interrupt Controllers 3-23

DMA Controller 3-23

A1 8 Memory Board 3-24

Address Latches 3-24

Address Decode and Memory Select 3-24

EPROMs, SRAM, and NVRAM 3-25

Memory Data Buffers 3-25

Wait State Generator 3-25

Wait State Diagnostics 3-25

Memory Configuration Readback 3-25

Battery Backup 3-25

A19 Strobe/TDR Buffer Board 3-26

Strobe Sense Select 3-26

Strobe Deskew 3-26

TDR Buffer and Level Shift 3-26

A20-23 Head Interconnect Boards 3-26

A26 M/F Acquisition Interconnect Board 3-27

A24/A27 & A25/A28 Acquisition System Boards 3-27

Programmable Gain Amplifiers 3-27

A/D Convertors 3-28

Measurement Hardware 3-28

Timing and Sampling Head Control 3-28

Shared RAM 3-29

Time Base/Controller Interface 3-29

Microprocessor 3-29

11801C Service Manual

Table of Contents

Performance Verification

Test Equipment 4-3

Test Record 4-6

Using These Procedures 4-11

Conventions in this Manual 4-11

Menu Selections and Measurement Techniques 4-11

User Manual 4-11

Performance Tests 4-13

Power-On Diagnostics 4-14

Setup to Invoke Power-On Diagnostics 4-14

Procedure to Invoke Power-On Diagnostics 4-14

Diagnostics 4-15

Self-Test Diagnostics 4-15

Power-On Diagnostics Complete 4-16

Sampling Heads 4-17

Setup to Calibrate a Sampling Head 4-17

Procedure to Calibrate a Sampling Head 4-17

Extended Diagnostics 4-19

Setup to Invoke Extended Diagnostics 4-19

Procedure to Invoke Extended Diagnostics 4-19

Vertical Reference Voltage 4-21

Specifications 4-21

Setup to Check Vertical Reference Voltage 4-21

Procedure to Check Vertical Reference Voltage 4-21

Horizontal Reference Clock 4-23

Specifications 4-23

Setup to Check Horizontal Reference Clock 4-23

Procedure to Check Horizontal Reference Clock 4-23

Vertical Accuracy 4-25

Setup to Check Vertical Gain 4-25

Procedure to Check Vertical Gain 4-25

Setup to Check Offset Accuracy 4-28

Procedure to Check Offset Accuracy 4-28

System Vertical RMS Noise 4-31

Setup to Examine Vertical RMS Noise 4-31

Procedure to Examine Vertical RMS Noise 4-31

Sweep Rate Accuracy 4-34

Setup to Examine Sweep Rate Accuracy 4-34

Procedure to Examine Sweep Rate Accuracy 4-34

Sweep Rate Accuracy 2 ns/div 4-35

Sweep Rate Accuracy 1 ns/div 4-36

Sweep Rate Accuracy 1 00 ps/div 4-36

Sweep Rate Accuracy 1 0 ps/div 4-36

Sweep Rate Accuracy 1 ps/div 4-37

Contents

Table of Contents

Triggering, Externai Direct 4-39

Specifications 4-39

Setup to Check Triggering 4-39

Procedure to Check Triggering 4-39

Prescaier Triggering 4-41

Specifications 4-41

Setup to Check Prescaler Triggering 4-41

Procedure to Check Prescaler Triggering 4-41

Internal Clock 4-43

Measurement Limits 4-43

Setup to Examine Internal Clock 4-43

Procedure to Examine Internal Clock 4-43

Calibrator Output 4-45

Measurement Limits 4-45

Setup to Examine Calibrator Output 4-45

Procedure to Examine Calibrator 4-45

Adjustment

Test Equipment 5-3

Using These Procedures 5-6

Conventions in this Manual 5-6

Menu Selections and Measurement Techniques 5-6

User Manual 5-6

Power Supply 5-7

Measurement Limits 5-7

Setup to Examine Voltage Supply 5-7

Procedure to Examine Voltage Supply 5-7

Setup to Examine/Adjust Voltage Reference 5-9

Procedure to Examine/Adjust Voltage Reference 5-9

Setup to Examine/Adjust Regulator Reference 5-11

Procedure to Examine/Adjust Regulator Reference 5-11

Display 5-13

Measurement Limits 5-13

Setup to Examine/Adjust the Display 5-14

Procedure to Examine/ Adjust the Display 5-14

Real Time Clock 5-20

Measurement Limits 5-20

Setup to Examine/Adjust Real Time Clock 5-20

Procedure to Examine/Adjust Real Time Clock 5-20

11801C Service Manual

vii

Table of Contents

Maintenance

Preventive Maintenance 6-1

Removing the Cabinet Paneis 6-1

Cieaning the instrument 6-2

Exterior 6-2

CRT 6-2

Interior 6-3

Visuai inspection 6-3

Periodic Electricai Adjustment 6-3

Corrective Maintenance 6-5

Power Suppiy Voitage Hazard 6-5

Ordering Parts 6-5

Static-Sensitive Device Ciassification 6-6

Removing and Replacing FRUs 6-8

Eiectrical Lock-on of the Front Panei ON/STANDBY

Power Switch 6-13

Power Suppiy Moduie Removai/Replacement 6-16

Fan Motor Removai/Repiacement 6-19

Cathode Ray Tube (CRT) Removai/Repiacement 6-20

Acquisition Unit Removai/Repiacement 6-26

Battery Disposai and First Aid 6-27

Battery Disposal 6-27

Emergency and First Aid Information 6-28

FRU Board and Assembly Removal 6-29

A1 M/F Strobe Drive Board 6-31

A3 M/F Power Connect Board 6-32

A4 Regulator Board 6-34

A5 Time Base/Controller Board 6-35

A7 CRT Socket Board and A8 CRT Driver Board 6-37

A9 Touch Panel Assembly 6-40

A10 Front Panel Control Board 6-42

A1 1 Front Panel Button Board 6-44

A1 2 Rear Panel Assembly 6-45

A1 3 Mother Board 6-47

A1 4 Input/Output (I/O) Board 6-49

A15 Memory Management Unit (MMU) Board 6-51

A1 7 Executive Processor (EXP) Board 6-53

A1 8 Memory Board 6-55

A1 9 Strobe/TDR Buffer Board 6-57

A20-A23 Head Interconnect Boards 6-59

A26 M/F Acquisition Interconnect Board 6-61

A24/A27 Acquisition Analog Boards 6-63

A25/A28 Acquisition MPU Boards 6-64

via

Contents

Table of Contents

FRU 1C Removal 6-65

Serial Data Interface Integrated Circuits (“Slam-Pack” ICs) . . 6-65

Firmware Integrated Circuits (“Dual In-Line Package” ICs) . . 6-68

Firmware Upgrade Procedure 6-69

Cables and Connectors 6-75

Interconnecting Pins 6-75

Coaxial-type End-Lead Connectors (Peltolas & SMB) 6-75

Multi-Pin Connectors 6-75

Checks After FRU Replacement 6-77

Diagnostic Troubleshooting 6-79

Diagnostics Overview 6-79

Kernel Diagnostics 6-80

Self-Test/Extended Diagnostics 6-81

Extended Diagnostics Menu Structure 6-81

Extended Diagnostics Error Index Codes 6-81

Diagnostic Menus 6-84

Diagnostic Menu Hardcopy 6-85

Diagnostic Terminal Mode (RS-232-C) 6-86

System Mode (GPIB & RS-232-C) 6-87

Battery Testing 6-89

Clearing NVRAM 6-90

Field Replaceable Unit (FRU) Guide 6-91

FRU Name Abbreviations 6-92

Component and Module Name Abbreviations 6-93

Executive Subsystem Error Index Codes 6-94

Display Subsystem Error Index Codes 6-98

Time Base Processor Error Index Codes 6-100

Acquisition Processor Error Index Codes 6-102

Other Troubleshooting 6-103

Power Supply Module 6-103

Module Troubleshooting 6-103

A4 Regulator Board 6-103

CRT, A7 CRT Socket Board, or A8 CRT Driver Board 6-104

Module Troubleshooting 6-104

A1 3 Mother Board 6-104

Fuse Testing 6-105

Time Base Calibration Errors 6-108

Acquisition Calibration Errors 6-110

Options

Instrument Options 7-1

Power Cord Information 7-2

11801C Service Manual

Table of Contents

Electrical Parts List

Electrical Parts 8-1

Diagrams

Replaceable Parts List

Replaceable Parts 10-1

Parts Ordering Information 10-1

Module Replacement 10-1

Firmware Replacement 10-1

Using the Repiaceable Parts List 10-2

Item Names 10-2

Indentation System 10-2

Abbreviations 10-2

Contents

List of Figures

Figure 2-1 : Sampling Head Compartments in the 11 801 C Digital

Sampling Oscilloscope 2-2

Figure 2-2: Power-Cord Plug Identification 2-5

Figure 3-1 : Trigger Edge Slew Rate for High Frequency Selection . . 3-10

Figure 4-1 : A26 M/F Acquisition Interconnect Board Test Point

Locations 4-22

Figure 4-2: A5 Time Base/Controller Board Test Point Locations . . . 4-24

Figure 5-1: A1 8 Memory Board Test Point Locations 5-8

Figure 5-2: A2A2 Control Rectifier Board Test Point and

Adjustment Locations 5-10

Figure 5-3: A4 Regulator Board Test Point and Adjustment

Locations 5-12

Figure 5-4: A8 CRT Driver Board Adjustment Locations 5-18

Figure 5-5: A7 CRT Socket Board Adjustment Locations 5-19

Figure 5-6: A14 I/O Board Test Point and Adjustment Locations .... 5-22

Figure 6-1: Field Replaceable Units (FRU) Locator 6-14

Figure 6-2: Removing the Power Supply Module, Fan Housing,

and Rear Panel Connector Plate 6-16

Figure 6-3: A2A2 Control Rectifier Board Connector Locations 6-17

Figure 6-4: Removing/Replacing the CRT Cover 6-23

Figure 6-5: Removing/Replacing the Cathode Ray Tube 6-24

Figure 6-6: Removing/Replacing the CRT Torx Head Screws 6-25

Figure 6-7: Top View of the Card Cage 6-30

Figure 6-8: Removing/Replacing the A1 M/F Strobe Drive Board . . . 6-31

Figure 6-9: Removing/Replacing the A4 Regulator Board 6-33

Figure 6-1 0: Removing/Replacing the A5 Time Base/Controller

Board 6-36

Figure 6-1 1 : Removing/Replacing the A7 CRT Socket Board 6-38

Figure 6-1 2: Removing/Replacing the A8 CRT Driver Board 6-39

Figure 6-13: A9 Touch Panel Assembly Torx Head Screws 6-41

Figure 6-14: Removing/Replacing the A9 Touch Panel Assembly . . . 6-41

Figure 6-1 5: Removing/Replacing the A1 0 Front Panel

Control Board 6-43

Figure 6-1 6: Removing/Replacing the A1 1 Front Panel

Button Board 6-44

Figure 6-17: Removing/Replacing the A12 Rear Panel Assembly . . . 6-46

Figure 6-1 8: Removing/Replacing the A1 3 Mother Board 6-48

Figure 6-1 9: Removing/Replacing the A1 4 I/O Board 6-50

Figure 6-20: Removing/Replacing the A1 5 MMU Board 6-52

1 1 801 C Service Manual x/

List of Figures

Figure 6-21 : Removing/Replacing the A1 7 Executive Processor

Board 6-54

Figure 6-22: Removing/Replacing the A1 8 Memory Board 6-56

Figure 6-23: Removing/Replacing the A19 Strobe/TDR Buffer

Board 6-58

Figure 6-24: Removing/Replacing the A20-A23 Head Interconnect

Boards 6-59

Figure 6-25: Removing/Replacing the Front Subpanel Assembly . . . 6-60

Figure 6-26: Removing/Replacing the A26 M/F Acquisition

Interconnect Board 6-61

Figure 6-27: Top View of the A26 Mainframe Acquisition

Interconnect Board 6-62

Figure 6-28: Removing/Replacing the A24/A27 Acquisition

Analog Boards 6-63

Figure 6-29: Removing/Replacing the A25/A28 Acquisition

MPU Boards 6-64

Figure 6-30: FRU 1C Detail 6-67

Figure 6-31 : 1C Insertion-Extraction Tool 6-69

Figure 6-32: Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

Figure 6-33: A1 7 Executive Processor Board Test Point and

Status LED Locations 6-95

Figure 6-34: A15 MMU Board Test Point and Status

LED Locations 6-99

Figure 6-35: A5 Time Base/Controller Board Status LEDs 6-101

Figure 6-36: A25/A28 Acquisition MPU Board Status LEDs 6-102

Figure 6-37: A1 4 I/O Board Fuse Locator Diagram 6-107

Figure 7-1 : Power-Cord Plug Identification 7-2

Figure 9-1 : 11801 C-System Functional Block Diagram 9-1

Figure 9-2: A1 M/F Strobe Drive Board Block Diagram 9-1

Figure 9-3: A4 Regulator Board Block Diagram 9-2

Figure 9-4: A5 Time Base/Controller Board Block Diagram 9-2

Figure 9-5: A7 CRT Socket Board Block Diagram 9-2

Figure 9-6: A8 CRT Driver Board Block Diagram 9-3

Figure 9-7: A1 2 Rear Panel Assembly Block Diagram 9-3

Figure 9-8: A1 4 I/O Board Block Diagram 9-4

Figure 9-9: A1 5 MMU Board Block Diagram 9-4

Figure 9-10: A1 7 Executive Processor Board Block Diagram 9-4

Figure 9-1 1 : A18 Memory Board Block Diagram 9-5

Figure 9-1 2: A1 9 Strobe/TDR Buffer Board Block Diagram 9-5

Figure 9-13: A26 M/F Acquisition Interconnect Board Block

Diagram 9-5

Figure 9-1 4: A24/A27 Acquisition Analog Board Block Diagram .... 9-6

Figure 9-1 5: A25/A28 Acquisition MPU Board Block Diagram 9-6

x/7 Contents

List of Figures

Figure 10-1: Cabinet 10-7

Figure 10-2: Front Panel 10-9

Figure 10-3: Chassis, Rear 10-11

Figure 10-4: Circuit Boards 10-13

Figure 10-5: Acquisition Module 10-17

Figure 10-6: Power Supply 10-19

Figure 10-7: Option 1M 10-21

Figure 10-8: Accessories 10-23

xiii

11801C Service Manuai

List of Figures

xtV Contents

List of Tables

Table 1-1 : Measurement Limits, Specifications, Adjustments,

and Functional Tests 1-1

Table 2-1 : Power-Cord Conductor Identification 2-5

Table 4-1 : Measurement Limits, Specifications, and

Functional Tests 4-1

Table 4-2: Test Equipment 4-3

Table 4-3: Voltage Source Settings 4-27

Table 4-4: Vertical Offset Test Values 4-30

Table 4-5: Sensitivity Settings 4-33

Table 4-6: Prescaler Test Settings 4-42

Table 5-1 : Measurement Limits and Adjustments 5-2

Table 5-2: Test Equipment 5-3

Table 6-1 : Relative Susceptibility to Damage from Static Discharge . 6-6

Table 6-2: FRU Removal/Replacement Figure Cross Reference .... 6-8

Table 6-3: Emergency Procedures for Contact with Battery Solvent . 6-28

Table 6-4: Checks Required After FRU Replacement 6-77

Table 6-5: Extended Diagnostics Error Index Code Descriptions ... 6-82

Table 6-6: System Mode Commands 6-87

Table 6-7: Event Code Descriptions 6-87

Table 6-8: Board FRUs 6-92

Table 6-9: Component Module FRUs 6-93

Table 6-10: Executive Processor Kernel Error Index Codes 6-94

Table 6-1 1 : Executive Processor Status LED Configuration 6-95

Table 6-12: Executive Processor Manual Tests 6-96

Table 6-13: Display Processor Kernel Error Index Codes 6-98

Table 6-14: Display Processor Status LED Configuration 6-98

Table 6-15: Time Base Processor Kernel Error Index Codes 6-100

Table 6-16: Acquisition Processor Kernel Error Index Codes 6-102

Table 6-17: A1 4 I/O Board Fuse Failures 6-106

Table 6-18: Time Base Calibration Errors 6-109

Table 7-1 : Power-Cord Conductor Identification 7-2

Table 10-1: Board FRUs 10-3

11801C Service Manual

List of Tables

xvi Contents

General Safety Summary

Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.

Only qualified personnel should perform service procedures.

While using this product, you may need to access other parts of the system. Read
the General Safety Summary in other system manuals for warnings and cautions
related to operating the system.

To Avoid Firo or Use Proper Power Cord. Use only the power cord specified for this product and
Personal Injury certified for the country of use.

Use Proper Voltage Setting. Before applying power, ensure that the line selector is
in the proper position for the power source being used.

Connect and Disconnect Properly. Do not connect or disconnect prohes or test
leads while they are connected to a voltage source.

Ground the Product. This product is grounded through the grounding conductor
of the power cord. To avoid electric shock, the grounding conductor must he
connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.

Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.

Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.

Use Proper Fuse. Use only the fuse type and rating specified for this product.

Avoid Exposed Circuitry. Do not touch exposed connections and components
when power is present.

Do Not Operate With Suspected Failures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.

Do Not Operate in Wet/Damp Conditions.

Do Not Operate in an Explosive Atmosphere.

Keep Product Surfaces Clean and Dry.

Provide Proper Ventilation. Refer to the manual’s installation instructions for
details on installing the product so it has proper ventilation.

11 801 C Service Manual

xvii

General Safety Summary

Symbols and Tarms Terms in this Manual. These terms may appear in this manual:

WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.

CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.

Terms on the Product. These terms may appear on the product:

DANGER indicates an injury hazard immediately accessihle as you read the
marking.

WARNING indicates an injury hazard not immediately accessihle as you read the
marking.

CAUTION indicates a hazard to property including the product.

Symbols on the Product. The following symbols may appear on the product:

□

WARNING

Protective

CAUTION

Double

High Volt-

Ground (Earth)

Refer to Manual

Insulated

age

Terminal

xWi7

Contents

Service Safety Summary

Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service
procedures.

Do Not Service Alone. Do not perform internal service or adjustments of this
product unless another person capable of rendering first aid and resuscitation is
present.

Disconnect Power. To avoid electric shock, disconnect the mains power by means
of the power cord or, if provided, the power switch.

Use Caution When Servicing the CRT. To avoid electric shock or injury, use
extreme caution when handling the CRT. Only qualified personnel familiar with
CRT servicing procedures and precautions should remove or install the CRT.

CRTs retain hazardous voltages for long periods of time after power is turned off.
Before attempting any servicing, discharge the CRT by shorting the anode to
chassis ground. When discharging the CRT, connect the discharge path to ground
and then the anode. Rough handling may cause the CRT to implode. Do not nick
or scratch the glass or subject it to undue pressure when removing or installing it.
When handling the CRT, wear safety goggles and heavy gloves for protection.

Use Care When Servicing With Power On. Dangerous voltages or currents may
exist in this product. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.

To avoid electric shock, do not touch exposed connections.

X-Radiation. To avoid x-radiation exposure, do not modify or otherwise alter the
high-voltage circuitry or the CRT enclosure. X-ray emissions generated within
this product have been sufficiently shielded.

11 801 C Service Manual

x/x

Service Safety Summary

Contents

Specifications

This section provides specifications for testing and adjusting your 1 1 801 C
oscilloscope. Refer to the 11 801 C L/ser Manua/ for a general description of
the characteristic, environmental, and user specifications of the oscillo-
scope. Table 1-1 lists measurement and specification values. Refer to the
Performance Verification section for Performance test procedures; refer to
the Adjustment section for Adjustment procedures.

Table 1-1: Measurement Limits, Specifications, Adjustments, and Functional Tests

Part and Description

Measurement
Limits (Examine)

Specifications

(Check)

Adjustments

(Adjust)

Functional

Test

Power-On Diagnostics

none

yes

Sampling Head

none

yes

Extended Diagnostics

none

yes

Power Supply

Voltage Supply

-1-4.85 V to
+5.25 V

none

Voltage Reference

-1-5.15 V to
+5.25 V

none

R800 -1-5.2 V Ref
for -1-5.20 V

Regulator Reference

-1-9.95 V to
-1-10.05 V

none

R730 -1-10 V Ref
for -1-10.00 V

Display

Cutoff

visible

none

SCREEN, on
transformer on A8
CRT Driver board,
until display
appears

Convergence

primary colors are not
separated in the white
grid

none

CCNVERGENCE,
R210,for
optimum
convergence of
red, green, and
blue

Focus

focused grid pattern

none

FCCUS, on
transformer on A8
CRT Driver board,
for optimum
focus on white
grid pattern

11801C Service Manual

7-1

Specifications

Table 1-1: Measurement Limits, Specifications, Adjustments, and Functional Tests (Cont.)

Part and Description

Measurement
Limits (Examine)

Specifications

(Check)

Adjustments

(Adjust)

Functional

Test

Display (Cont.)

Vertical Size and
Position

align with tic marks

none

VERT SIZE, L321 ;
and VERT POS,
R31 1 ; for
optimum
alignment

Horizontal Size,
Linearity and
Position

align with tic marks and
for optimum
appearance

none

H-SIZE, R501;
H-LIN, R502; and
H-POS, R500; for
optimum
alignment and
linearity

Gray Scale

white at the top of the
display and gray at the
bottom, and the right
side of the display is
cut off

none

SCREEN, on
transformer on A8
CRT Driver board;
RED, R200;
GREEN, R201;
and BLUE, R203;
for cutoff and
color balance

Color Impurity

no severe color
impurities in red, green,
and blue display

none

cycle power on
and off

Real Time Clock

1,000,000 ps ±5 ps

none

Real Time Clock
for 1 ,000,000 ps

Vertical Reference Voltage

none

5 ±200 pV and
-5 ±200 pV

none

Horizontal Reference Clock

none

200,000 kHz
±5 kHz

none

Vertical Accuracy

Vertical Gain

none

±1.0% full scale

none

yes

Offset Accuracy

none

±2 mV

none

yes

Vertical Linearity

none

±1%

none

System Vertical RMS Noise

200 pV at 2 mV/div
500 pV at 5 mV/div
1 mV at 10 mV/div
632 pV at 20 mV/div
1 .58 mV at 500 mV/div
3.16 mV at 100 mV/div
6.32 mV at 200 mV/div

none

yes

1-2

Specifications

Table 1-1: Measurement Limits, Specifications, Adjustments, and Functional Tests (Cont.)

Part and Description

Measurement
Limits (Examine)

Specifications

(Check)

Adjustments

(Adjust)

Functional

Test

Sweep Rate Accuracy

0.05% at 2 ns/div
0.08% at 1 ns/div
0.8% at 100 ps/div
2.5% at 10 ps/div
10% at 1 ps/div

none

yes

Triggering, External Direct, XI Attenuation

yes

300 MHz Sensitivity

100 mVp.pat300 MHz

1 00 mV stable
display

none

1000 MHz Sensitivity

100 mVp.pat1000 MHz

1 00 mV stable
display

none

3.0 GHz Sensitivity

100 mVp.p at 3.0 GHz

1 00 mV stable
display

none

Prescaler Triggering

800 mVp.p at 2 GHz

800 mV stable
display

none

yes

600 mVp_p at 3 GHz

600 mV stable
display

none

600 mVp_p at 1 0 GHz

600 mV stable
display

none

Internal Clock

yes

Rise Time

<2.5 ns

none

Frequency

100 kHz ±3%

none

Duty Cycle

50% ±3%

none

Calibrator Output

yes

Rise Time (typical)

250 ps

none

Peak-to-peak Amplitude

250 mV ±10%

none

11801C Service Manuai

7-3

Specifications

1-4

Specifications

Operating Information

The 1 1801C Digital Sampling Oscilloscope Service Manual is designed for
use by qualified service personnel. It contains information necessary to
check, troubleshoot, and maintain the 11801C Digital Sampling Oscillo-
scope.

Troubleshooting is primarily based upon internal power-on diagnostics.
These diagnostics isolate problems to the field replaceable unit (FRU) level.
Defective FRUs not detected by diagnostics are isolated using other means.
Once the faulty FRU is identified, use the instructions provided in this manu-
al to remove and replace it. The removal and immediate replacement of the
faulty FRU allows a minimum of downtime for the user. The Parts List section
gives a complete list of the FRUs in this instrument.

First-time users are encouraged to read the 1 1801C Digital Sampling Oscil-
loscope User Manual. This will help you to learn the basic functions of the
118010.

This section contains information about installing and removing a sampling
head, applying power, proper environmental conditions, shipping the instru-
ment, and instrument options.

11 801 C Service Manual

2-1

Operating Information

Sampling Head
Installation and
Removal

To avoid damage to the oscilloscope, set the ON/STANDBY switch to
STANDBY before installing or removing sampling heads.

Applying a voltage outside the range printed on the sampling head
can result in damage. Static electricity is also a hazard.

The input diodes used in the sampling heads are very susceptible to dam-
age from overdrive signal or DC voltages, and from electrostatic discharge.
Never apply a voltage outside the range printed on the front of the sampling
head. Operate the 1 1801 C only in a static-controlled environment.

Connect the wrist strap provided with the 1 1 801 C to the ANTISTATIC CON-
NECTION, as shown in Figure 2-1 . Refer to the 1 1801C Digital Sampling
Oscilloscope User Manual tor more information.

The SD-Series sampling head slides into one of the front panel compart-
ments of the 1 1 801 C Digital Sampling Oscilloscope. Figure 2-1 shows the
front panel of the 11801C Digital Sampling Oscilloscope and the locations of
the sampling head compartments.

Sampling Head
Compartments

Antistatic

Connection

Figure 2-1: Sampling Head Compartments in the 11 801 C Digital
Sampling Oscilloscope

2-2

Operating Information

With the ON/STANDBY switch set to STANDBY, place the sampling head in a
compartment and slowly push it in with firm pressure. Once the sampling
head is seated, turn the lock-down screw to tighten the sampling head in
place.

Never install or remove a sampling head when the ON/STANDBY
switch is ON. Installing or removing a sampling head when the
power is on may damage the oscilliscope.

To remove the sampling head, set the ON/STANDBY switch to STANDBY.
Turn the lock-down screw to loosen the sampling head, and then slowly pull
out the sampling head.

11801C Service Manual

2-3

Operating Information

Power Information

The rear panel LINE VOLTAGE SELECTOR allows you to select either a
1 1 5 V or 230 V (48 Hz to 440 Hz) nominal supply source. The 6 A, 250 V line
fuse is used for both 115V and 230 V operation.

^ARNIN^

GROUNDING. For electric shock protection, make the grounding
connection before making any connection to the instrument’s input
or output terminals. This instrument is safety Class 1 equipment
(lEC designation). All accessible conductive parts are directly
connected through the grounding conductor of the power cord to
the grounded (earth) contact of the power plug.

Any interruption of the grounding connection can create an electri-
cal shock hazard. The power input plug must be inserted only in a
mating receptacle with a grounding contact where earth ground
has been verified by a qualified service person. Do not defeat the
grounding connection.

WARNING

AC POWER SOURCE AND CONNECTION. An improper voltage
supply can damage the instrument. The instrument operates from a
single-phase power source. It has a three-wire power cord and
two-pole, three-terminal grounding type plug. The voltage to
ground (earth) from either pole of the power source must not
exceed the maximum rated operating voltage, 250 V.

Before making connection to the power source, check that the LINE
VOLTAGE SELECTOR is set to match the voltage of the power
source and has a suitable two-pole, three-terminal grounding-type
plug.

2-4

Operating Information

Power Cord
Information

A power cord with appropriate plug configuration is supplied with each
instrument. Table 2-1 , Power-Cord Conductor Identification, gives the color-
coding of the conductors in the power cord. If you require a power cord
other than the one supplied, refer to Figure 2-2, Power-Cord Plug Identifica-
tion.

Table 2-1 : Power-Cord Conductor Identification

Conductor

Color

Alternate Color

Ungrounded (Line)

Brown

Black

Grounded (Neutral)

Light Biue

White

Grounded (Earth)

GreenAfeliow

Green

standard*
North American
115V

Option A1
Universai Euro
230V

Option A3
Austraiian
230V

Option A4*
North American
230V

230V

Option 1A*
North American
115V/High Power

Option IB
North American
3-Phase

* Canadian Standards Association certification
inciudes these power piugs for use in the
North American power network

Figure 2-2: Power-Cord Plug Identification

11801C Service Manual

2-5

Operating Information

Memory Backup
Power

There are four batteries within the instrument that allow the retention of
volatile memory upon loss of the AC power source. These self-contained
power sources provide memory backup power to retain the following:

■ front-panel settings

■ stored settings

■ stored waveforms

■ Time & Date parameters

■ Time Base Cal Constants (these are regenerated automatically if lost)

■ the number of hours of instrument on-time, power-on sequences, and
instrument serial number

The batteries have a nominal shelf life of approximately five years.

Operating

Environment

The following environmental requirements are provided so that you can
ensure proper functioning and extend the operation of the instrument.

Operating Temperature

The instrument can be operated where the ambient air temperature is be-
tween 0° C and -i-50° C and can be stored in ambient temperatures from
-40° C to -1-75° C. After storage at temperatures outside the operating
limits, allow the chassis to reach the safe operating temperature before
applying power.

Ventilation Requirements

The fan draws air through the side panels of the instrument and blows air
out through the rear to cool the instrument. To ensure that this cooling
process occurs properly, allow at least two inches clearance on both sides
and the rear of the instrument. The top and bottom of the instrument do not
require ventilation clearance.

If air flow is restricted, then the instrument’s power supply may
temporarily shut down.

2-6

Operating Information

Packaging for
Shipment

If the instrument is to be shipped for long distances by commercial trans-
portation, it should be packaged in the original manner. The carton and
packaging material in which your instrument was shipped should be saved
and used for this purpose.

Also, if the instrument is to be shipped to a Tektronix service center for
service or repair, attach a tag to the instrument showing the following:

■ owner of the instrument (with address)

■ name of person to contact at your firm

■ complete instrument type and serial number

■ if possible, furnish complete system firmware versions as displayed in
the Instrument Options pop-up menu selected from the UTILITY major
menu

■ a description of the service required

If the original packaging is unfit for use or not available, package the instru-
ment as follows:

r~l Step 1 : Obtain a corrugated cardboard shipping carton with a

375-pound test strength and having inside dimensions at least six in-
ches greater than the instrument dimensions. This allows for cushioning.

I I Step 2: Wrap the instrument with polyethylene sheeting or equivalent
material to protect the finish.

I I Step 3: Cushion the instrument on all sides by tightly packing dunnage
or urethane foam between the carton and the instrument, allowing three
inches on each side.

I I Step 4: Seal the carton with shipping tape or with an industrial stapler.

I I steps: Mark the address of your local Tektronix service center and your
return address on the carton in one or more prominent locations.

11801C Service Manual

2-7

Operating Information

2-8

Operating Information

Theory of Operation

The Tektronix 11 801 C is a high-resolution digital sampling oscilloscope
accommodating up to eight input channels through the dual-channel sam-
pling heads. With the SD-24 TDR/Sampling Head, eight channels of single-
ended TDR or four channels of differential TDR are available as well.

Features include the following:

■ sweep rates ranging from 5 ms/division to 1 ps/div

■ autoset to provide a suitably adjusted display for viewing and further
manual adjustment

■ windows for viewing expanded sections of a trace

■ self-tests to assure continuous accuracy of waveform data and measure-
ments

■ digital waveform storage and display

■ on-board measurement capabilities

■ menu-driven touch-screen operation

■ RS-232-C, GPIB, and PRINTER interfaces
This section has two main sub sections:

■ System Functional Overview describes the major functional blocks of
the 1 1 801 C and presents a typical waveform processing cycle

■ Block Diagram Descriptions discusses the individual boards in the
11801C

11801C Service Manual

3-1

Theory of Operation

3-2

Theory of Operation

System Functional Overview

This section describes and illustrates the major functional blocks of the
11801C (see Figure 9-1).

Acquisition System
Biock

The 1 1801 C contains two identical Acquisition systems. Each Acquisition
system supports two dual-channel sampling heads for four overall channels.
However, each Acquisition system contains only two physical channels that
can be used for data acquisition and measurement.

Since each Acquisition system supports four input channels (two dual-chan-
nel heads) but contains only two acquisition/measurement channels, the
four input channels are multiplexed into the two acquisition/measurement
channels through analog multiplexers. Any one of the four sampling head
input channels can be independently connected to either of the two acquisi-
tion/measurement channels.

Several calibration signals are also supplied to each multiplexer, although
these signals are used only for self-tests and diagnostics.

Strobe Distribution
Biock

The Strobe Distribution block acts as an interface between the Time Base/
Controller and the Acquisition systems.

The Time Base/Controller generates a strobe pulse that is regenerated by
the Strobe Distribution block to drive all of the sampling heads in parallel.

Tim© BaSO/Controiior The Time Base/Controller block is comprised of:
Biock ■ a microprocessor with local RAM and ROM

■ the time base and trigger circuits

■ interfaces to the memory management unit (MMU) and Acquisition
systems

Triqqor Ssioct Biock Trigger select block selects the desired trigger signal to be sent to the

Time Base/Controller block.

11801C Service Manual

3-3

System Functional Overview

Executive Processor
Block

After the user requests an operation (with a front panel control, for instance),
the Executive Processor (EXP) directs the oscilloscope to perform this
operation. Another primary function of the EXP is to execute diagnostic
Self-Tests on the instrument when powering-on or at the user’s request. To
control operations, the EXP controls and monitors the other circuit boards
sharing the executive system bus. Through the executive bus boards, the
EXP also indirectly controls all other instrument boards. The EXP generates
commands and status signals to control on-board devices and I/O devices,
such as GPIB and RS-232-C interfaces, that help process data and help
control the rest of the instrument.

Memory Management
Unit Block

The memory management unit (MMU) arbitrates requests for access to the
Waveform Memory from the following three sources:

■ the EXP

■ the Time Base/Controller

■ the display system

This arbitration allows all three systems transparent access to the Waveform
Memory.

Wavoform Momory waveform Memory is shared among the following three processors:

Block ■ the EXP

■ the Display

■ the Time Base/Controller

While the main function of the Waveform Memory is the storage of waveform
data and waveform related information, the shared memory is also used to
pass messages between the Executive, Display, and Time Base/Controller
processors. Eventually, all acquired waveforms are transferred from the
Acquisition system memory to the Waveform Memory for display.

3-4

Theory of Operation

System Functional Overview

Front Panol Controls user control of the oscilloscope is primarily through the following three front

panel controls:

■ the front-panel major-menu buttons

■ the touch panel

■ the multifunction knobs

The major menu buttons are the top level menu selections for the instru-
ment. Touching an icon, menu item, or waveform selects that particular icon,
menu item, or waveform, respectively. The multifunction knobs control the
function of the particular item that is selected.

I/Q Block block provides a GPIB port, RS-232-C port, and a PRINTER port for

interfacing various I/O devices to the instrument.

Waveform
Compressor and
Display Control Block

The display subsystem provides all visual output to the user. This includes
not only data output such as waveform traces, graticules, axes, and annota-
tion, but displays supporting the human interface as well (which includes
menus, labeling for touch panel input, and an interactive output to assist in
operating the system; that is, the current mode-setting information).

The oscilloscope uses a custom vertical raster-scan display that provides
excellent resolution for both waveform display and text. The display system
produces a display by:

1 . transferring waveform data from the Waveform Memory

2. compressing it into 512 horizontal pixels

3. converting it to a format compatible with the vertical raster-scan display

The Waveform Compressor takes waveforms with more than 512 data points
and compresses these points into 512 groups. For example, for a 1024-point
waveform, each group would contain two points; for 2048-point waveforms,
each group would contain four points. The Waveform Compressor finds the
largest and smallest vertical value in a group of points and then draws a
vector between the maximum and minimum — even in “dots” mode. The
only difference between dots and vectors is that in vector mode the vectors
are extended vertically to meet the vector on the next scan line.

11 801 C Service Manual

3-5

System Functional Overview

Power Supply

To apply power to the instrument:

1 . Turn the rear panel PRINCIPAL POWER switch to ON.

2. Turn the front panel ON/STANDBY switch to ON.

A small green indicator lamp should light, indicating the power is on.

The oscilloscope operates from either a 1 15 V or 230 V nominal line voltage
source at a line frequency between 48 Hz and 440 Hz. The LINE VOLTAGE
SELECTOR switch allows selection of AC line inputs of 90 V to 132 Vrms o'"
180 V to 250 Vrms-

Typical Waveform
Processing Cycle

The following is a brief overview of how the oscilloscope acquires, pro-
cesses, and displays a waveform from the input channels:

1 . Analog input signals are connected to the sampling head inputs.

2. The Time Base/Controller block produces precisely timed strobe signals
based on the trigger signal.

3. These strobe signals are distributed to the sampling head channels and
instruct the sampling heads when to take samples of the input signal.

4. The Acquisition systems take the output of the sampling heads, amplify
or attenuate the signals, and apply any offset based on the vertical size
and position controls.

5. The output of the amplifiers are applied to analog-to-digital (A/D) con-
verters, which convert the sampled voltages to digital codes and then
store these codes in the acquisition system memory.

6. Once all the samples in a waveform have been acquired, the Time
Base/Controller then transfers these samples from the Acquisition sys-
tem memory to the Waveform Memory, through the waveform data
direct memory access (DMA).

7. The EXP processes information from the human interfaces (that is; the
menus, icons, buttons, and knobs that you interact with to control the
oscilloscope).

8. The EXP sends commands to the display system so that the function
that the user selected is displayed.

9. When instructed by the EXR the display system receives the waveform
data from waveform memory and converts it to a unique vertical raster-
scan format for a display based on the user’s settings.

3-6

Theory of Operation

Block Diagram Descriptions

A1 M/F Strobe Drive
Board

This section describes the 11 801 C board level block diagrams (see the
Diagrams section) .

The A1 M/F Strobe Drive board consists of the following circuits:

■ Data buffers circuitry

■ Address latch circuitry

■ Function decoder circuitry

■ Internal clock rate generator circuitry

■ Control buffers circuitry

See Figure 9-2 for a block diagram of this board.

Data Buffers

This circuit buffers the A5 Time Base/Controller board’s address and data
buses with bidirectional buffers, and the A5 Time Base/Controller board’s
control lines with octal buffers.

Address Latch

This circuitry buffers and latches the address for the A5 Time Base/Control-
ler board to use.

Function Decoder

This circuit partially decodes this latched address and enables the data
buffers if the address is on this board or on the A24/A27 & A25/A28 Acquisi-
tion system boards (controlled through this board). The function decoder
also selects the appropriate direction of the data buffers to perform a read or
write operation.

Internal Clock Rate Generator

This circuit is a 1 6-bit programmable counter that is tied to the ^ 2 flip-flop
which produces the square wave output. The overall division ratio of this
block can be programmed from 2^ to 2''^. The internal clock rate generator
is programmed at power-on to provide a 100 kHz output, given a 4 MHz
input on jumper J35.

11801C Service Manual

3-7

Block Diagram Descriptions

A3 M/F Power
Connect Board

A4 Regulator Board

Control Buffer

This circuit buffers the control signals sent to the At M/F Strobe Drive board
from the A5 Time Base/Controller board.

The A3 M/F Power Connector board consists of built-in connectors that
connect the power supply voltages from the A4 Regulator board to the
following boards:

■ A1 M/F Strobe Drive board

■ A5 Time Base/Controller board

■ A26 M/F Acquisition Interconnect board

The A3 M/F Power Connect board also supplies ±15 V power to the A14
Input/Output (I/O) board through a 16-pin ribbon cable.

The regulators convert semi-regulated voltages into stabilized, low-ripple,
output voltages. The A4 Regulator board consists of the following regulators
and the voltage-fault detect circuitry:

■ +50 V

■ -15 V

■ +5 V

■ +15 V

■ -50 V

See Figure 9-3 for a block diagram of this board.

The operational amplifiers used for the +50 V, +15 V, +5 V -50 V, -15 V,
and -5 V regulators require that the following special voltages be generated
for their operation:

■ semi-regulated +54 V supply generates the +20 V supply

■ semi-regulated -54 V supply generates the -20 V supply

■ semi-regulated +54 V supply generates the + 1 0 V supply

■ semi-regulated -54 V supply generates the - 1 0 V supply

■ +10.0 REF is used as a reference voltage

Voltage Fault Detect

This circuit consists of two window comparators and associated resistors.
This circuitry detects if any regulated supply is over-voltage or under-voltage.
The associated resistors set a hysteresis window that is 5% of the regulator
sense line voltages.

3-8

Theory of Operation

Block Diagram Descriptions

A5 Time

Base/Controller

Board

The A5 Time Base Controller board consists of the following circuitry:

■ Microprocessor (MPU)

■ RAM/ROM

■ Trigger circuitry

■ Time Base circuitry

■ Acquisition system interface

■ Memory management unit (MMU) interface
See Figure 9-4 for the block diagram of this board.

Microprocessor

The microprocessor controls the time base and trigger circuitry in response
to commands from the Executive Processor, performs local on-line calibra-
tion of the time base, schedules waveform acquisitions, and manages the
Acquisition system and waveform data transfers.

RAM/ROM Memory

Both RAM and ROM memory reside within the microprocessor’s 1 Mbyte of
address space. The upper 256 Kbytes is reserved as ROM, the lower
1 28 Kbytes of static RAM is provided for dynamic data storage and local
nonvolatile memory. There are 32 Kbytes of memory-provided communica-
tion and waveform storage for the 1 1801C’s eight channels, and another
32 Kbytes for the Strobe Distribution block of the oscilloscope and multiplex-
ers. There are 512 Kbytes of memory assigned as communication and
primary waveform storage. Another 32 Kbytes are used to map the commu-
nication buffer of the parallel interface with the memory management unit,
and the remaining 32 Kbytes are divided into I/O space and time base
control.

Trigger

This circuit is comprised of the trigger recognizer and gated voltage control
oscillator. The trigger circuits accept trigger signals from the trigger attenua-
tor. The strobe sense signal and internal feedback signals are used in the
Self-Tests diagnostic process but are not normally used for data acquisition.

The trigger recognizer sees a valid direct trigger signal and outputs this
signal to the voltage controlled oscillator which sets the timing for the strobe
signal.

The direct trigger input allows programmed slope, level, AC/DC, and X1/X10
selection.

If auto trigger mode is selected, the timebase will generate its own trigger
signal after 20 ms. If normal trigger mode is selected, the 1 1 801 C will wait
for trigger signals.

11 801 C Service Manual

3-9

Block Diagram Descriptions

The High Frequency On/Off Control selects the state of the trigger hysteresis
in the trigger input path.

High Frequency On removes trigger hysteresis and improves sensitivity
when the trigger signal edge slew rate is 1 V/ns or greater, typically a
320 mVp.p, 1 GHz sine wave. See Figure 3-1 .

High Frequency Off retains trigger hysteresis while improving noise rejection
at low frequencies, when the trigger edge slew rate is less than 1 V/ns. It
can be used at any frequency if the trigger signal amplitude reliably triggers
the 1 1 801 C. See Figure 3-1 . This is the default setting after initialization.

Figure 3-1: Trigger Edge Slew Rate for High Frequency Seiection

The Enhanced Triggering ON/Off Control selects the state of the metastable
trigger rejection feature in the trigger input path.

Enhanced Triggering On directs the timebase to detect metastable trigger
events and reject the acquired data. The data is reacquired at the next
trigger event.

Enhanced Triggering Off allows the timebase to acquire and display metast-
able trigger events.

The Trigger Holdoff Control in the trigger menu programs the trigger holdoff
value.

Auto Holdoff is the default mode. This mode automatically programs Actual
Holdoff to the minimum possible value. It depends only on the time base
settings and is updated when the Main Size and Main Position values
change. Triggering is held off to beyond the rightmost point in the Main
record. The minimum value is 5 ps. The Actual Holdoff (auto mode) calcula-
tion is:

Actual Holdoff (auto mode) = max (5 ps, 5 ps-i-Main Pos-i- Duration)
where Duration = Main SizexlO divisions.

3-10

Theory of Operation

Block Diagram Descriptions

Manual Holdoff extends the trigger holdoff to longer periods, up to 2.5
seconds. The Actual Holdoff value depends on the value of Requested
Holdoff in addition to the time base settings. The Actual Holdoff (manual
mode) calculation is:

Actual Holdoff (manual mode) = max (5 ps, 5 ps+Main Pos+Duration,
Requested Holdoff)

Time Base

This circuit is a very precise slewing delay generator. It accepts triggers from
the reference oscillator, generates a precise delay, and outputs a strobe-
drive pulse.

The time base circuitry consists of a TECL integrated circuit (1C), which
contains three six-bit high-speed counters, and a CMOS 1C, which contains
a 48-bit programmable strobe delay generator.

On the first sample of the waveform, the sample is taken immediately after a
starting delay. Subsequent samples are delayed by an small additional
amount, called the dot delay. The dot delay is programmed and stored into
the strobe delay register. Each sample is delayed by one delay more than
the previous sample. The dot delay can vary from 1 0 fs to 20 ns depending
on the horizontal size and the number of points in the waveform record.

The sampling interval (incremental delay between samples) is the total
acquisition time (time/division x 10 divisions) divided by the number of
points acquired.

Acquisition System Interface

This circuit contains 16 Kbytes of RAM (physically located on the A25/A28
Acquisition MPU board) that is shared between the Acquisition system and
the Time Base/Controller. This RAM is mapped into the microprocessor
memory space so that it can be accessed as any other RAM — either by the
microprocessor, itself, or by the DMA controller.

This shared memory allows the microprocessor to transfer waveforms from
the Acquisition system to the Waveform Memory using DMA. It also provides
a mailbox structure for commands and data passed between the two sys-
tems.

Memory Management (MMU) Interface

This circuit interfaces the Time Base/Controller to the EXP and the Waveform
Memory. This interface allows the EXP to send commands to the micropro-
cessor through the Time Base/Controller and provides the path for waveform
transfers from the Acquisition system to the Waveform Memory.

11801C Service Manual

3-11

Block Diagram Descriptions

yyy QRX S0Ck©t Board socket board is an interface from the A15 MMU board to the

CRT. The A7 CRT Socket board consists of the following circuits:

■ Red, Green, and Blue video amplifiers

■ RED, GREEN, and BLUE cutoff adjustments

■ CONVERGENCE adjustment

See Figure 9-5 for a block diagram of this board.

Red, Green, and Blue Video Amplifiers

These three circuits are identical high speed video amplifiers that drive the
three cathodes (R, G, and B; red, green, and blue, respectively) of the CRT.
Each of the three colors can be programmed to display 64 different levels.
This yields a possible 262,144 colors, of which eight can be displayed on
the screen at any time.

Red, Green, and Blue Adjustments

These three potentiometers control the cutoff point; that is, the point at
which a certain color becomes invisible.

Convergence Adjustment

This potentiometer controls the vertical convergence of the red, green, and
blue deflection beams.

3-12

Theory of Operation

Block Diagram Descriptions

A8 CRT Driver Board

The A8 CRT Driver board consists of the following circuits:

■ Horizontal sweep circuitry

■ Vertical sweep circuitry

■ High voltage and grid voltage generator circuitry

■ Degauss circuit

■ Beam current limit circuit

■ Grid bias circuit

The A8 CRT Driver board circuitry drives the raster scan CRT. The VIDEO
and SYNC signals from the At 5 MMU board generate the Z-axis signal,
sweep signals, and grid bias voltages for the CRT.

See Figure 9-6 for a block diagram of this board.

Horizontal Sweep

This circuit generates the sweep current for the horizontal deflection yoke.
The horizontal driver includes an oscillator, a voltage ramp generator, a
high-gain amplifier, and a flyback generator. These components provide
sweep synchronization, horizontal deflection, and linearity.

The horizontal adjustments, H-SIZE, H-POS, and H-LIN, allow you to opti-
mize the appearance of the display.

Vertical Sweep

This circuit produces a deflection current that sweeps the video beam from
the bottom to the top of the CRT. This circuit also produces a flyback signal
for the flyback transformer that is in parallel with the deflection yoke.

The vertical adjustments, VERT SIZE and VERT PCS, set the vertical size
and position of the display.

High Voltage and Grid Voltage Generator

This circuit includes the flyback transformer which generates the 16 kV CRT
anode potential and other bias voltages. This transformer is coupled and
synchronized with the vertical deflection system.

The SCREEN adjustment provides the cutoff point; that is, the point where
no information is visible on the display screen. The FOCUS adjustment
provides manual focusing of the display image.

11 801 C Service Manual

3-73

Block Diagram Descriptions

A9, A10, and A11
Front Panel Boards

Degauss

This circuit removes magnetic fields from the color steel aperture grille.
These magnetic fields are induced at each power-on by magnetic sources.

The Degauss circuit produces an exponentially decaying sine wave with a
frequency of approximately 3.7 kHz. This waveform is applied to the de-
gauss coils that are located on both sides of the CRT. The decayed oscilla-
tion through the coils causes a magnetic field to be induced in the CRT steel
aperture grille. This magnetic field saturates the steel, and then forces the
stored magnetic field down to zero as the steel is driven around its hystere-
sis curve.

Beam Current Limit

This circuit limits the average power to the CRT to less than 15 W. An ampli-
fier circuit compares the sum of the anode current and the FOCUS adjust-
ment current to a reference current of 0.72 mA. If the sum of the two
currents exceeds the reference current, then the three video amplifiers on
the A7 CRT socket board are disabled.

Grid Bias

This circuit provides -40 V of grid bias to the A7 CRT Socket board. At
power-off, the grid is supplied with -90 V until the focus circuit discharges a
high voltage. This prevents a bright spot from appearing at the center of the
screen at power-off.

The A9, A10, and A1 1 Front-Panel Circuit boards specifically consist of the:

■ A9 Touch Panel assembly

■ A10 Front Panel Control board

■ A1 1 Front Panel Button board

Touch Panei, Major Menu Keys, and Menu Status LEDs

These three functions interface to the Executive processor through a general
purpose programmable keyboard and display controller 1C on the A10 Front
Panel Controller board.

The keyboard function of the 1C handles the touch matrix and hard keys.

The display function drives the menu LED light bars.

A9 Touch Panel Assembly

This circuit is comprised of infrared LEDs that produce a matrix of light
beams that are interrupted when the user touches a particular touch zone.
The touch panel and hard key matrix are scanned continuously until a
shadow or keypress is detected. When a hit is detected, that scan is com-

3-14

Theory of Operation

Block Diagram Descriptions

pleted and the interrupt line is asserted by the display controller. During this
time the interrupt is active and no new data is written into the sensor RAM
from the touch panel or hard keys even though the hardware continues to
scan; therefore, the data will not change in the sensor RAM while the micro-
processor is reading it.

Only one infrared LED is turned on at a time and only the phototransistor
directly opposite is selected to receive light. This prevents any crosstalk
between emitter/detector pairs.

A10 Front Panel Control Board

This circuitry generates the 6-bit address bus that is used to select an in-
frared LED and its compliment phototransistor on the A9 Touch Panel board.

A1 1 Front Panel Button Board

This circuitry is comprised of the major menu LED light bars which are
driven by the display refresh register output of the A7 Display Controller
board. Internally, there is a matrix of display RAM organized in an 8-bit by
8-bit matrix. This display RAM is scanned column by column (automatically);
lighting the appropriate LED bar(s) when a high bit is encountered. The
coarse/fine LEDs are driven by a latch which is controlled by the EXR The
coarse/fine selections are sensed on the A9 Touch Panel board.

A12 Rear Panel
Assembly

The At 2 Rear Panel assembly links the oscilloscope to other devices. This
assembly contains connectors for the following devices:

■ One GPIB Port

■ One RS-232-C Port

■ One Printer Port (Centronics style)

The At 2 Rear Panel assembly is controlled from the A14 Input/Output (I/O)
board through a 40-wire cable. This cable carries the following signals:

■ Eight-bit bidirectional data bus

■ Four-bit address bus

■ Four interrupt lines

■ GPIB DMA request and grant lines

■ Four device control lines

■ Assorted power supply and ground lines

See Figure 9-7 for a block diagram of this assembly.

11801C Service Manual

3-15

Block Diagram Descriptions

GPIB Data and Address Bus

This bus drives the GPIB controller directly. Control signals DBIN, and WR
are used by the GPIB controller to determine if the microprocessor is trying
to read from or write to it. The interrupt controllers in the A17 Executive
Processor board monitor this interrupt line and will signal the microproces-
sor to service the GPIB controller. In order to communicate with the micro-
processor, the GPIB controller requires that at least one of the following
conditions occurs:

■ the receiver section of the GPIB controller has a byte of data (Inbyte
Register) from the GPIB bus that the microprocessor needs to read

■ the transmitter section register (Outbyte Register) is empty and is ready
to receive another byte of data

■ the status of the GPIB bus or the GPIB controller has changed and the
microprocessor has to be notified

On the opposite side of the GPIB controller is another bus system. This
other bus system includes an eight-bit data bus which accesses a bidirec-
tional GPIB data buffer and an eight-bit control bus which accesses a GPIB
control driver. The GPIB bus is connected to the opposite side of the buffer
and control driver. These two devices are specially designed to be TTL
signal-level compatible on the bus side of the buffer driver.

The states of three control signals from the GPIB controller, SRQ, NRFD and
NDAC, are monitored and displayed on the rear panel of the oscilloscope.
These LEDs show the state that the GPIB controller is in, not the state of the
GPIB bus.

Two other signals of interest are GPIB RQ and GPIB GR. These signals are
used by the DMA Controller on the A17 Executive Processor board to com-
municate with the GPIB controller. The DMA can be programmed by the
microprocessor to service either the Inbyte register or the Outbyte register.

Standard RS-232-C Controller

This communications controller is connected to the same data bus and
address bus as the GPIB controller. The RPD7-RPD0 address lines transfer
data to and from the microprocessor. The RPA1-RPA4 address lines are
used by the microprocessor to select individual registers in the GPIB control-
ler. The STD RS SEL line goes low when the microprocessor wants to com-
municate with the RS-232-C controller. (This line also drives the Chip
Enable.)

The RD and WR signals are driven by the microprocessor to signal if the
GPIB controller is to be read from or written into. The controller sets the STD
RS INTR (interrupt) line low to request service from the microprocessor. The
microprocessor writes a byte into the controller’s transmit buffer to transmit
data on the RS-232-C bus. The microprocessor reads a byte from the receiv-
er buffer to receive data from the RS-232-C bus. The microprocessor can

3-16

Theory of Operation

Block Diagram Descriptions

A13 Mother Board

also read the status of the controller. The RS-232-C controller translates the
parallel data from the microprocessor to serial data from RXD on the
RS-232-C bus to parallel data for the microprocessor.

There are transmit and receive buffers which are compatible with the
RS-232-C bus. Clear To Send (CTS) and Data Set Ready (DSR) are
RS-232-C control signals that can be controlled by the microprocessor.
Request To Send (RTS) and Data Terminal Ready (DTR) are signals that can
be read by the microprocessor. The Received Signal Detect (RSD) control
signal is always high when power is on. This RS-232-C port is a DCE type.

Printer Port

The Centronics-style, J1 1 1 , printer port is controlled by a programmable
peripheral interface IC. This IC has all the control lines necessary to connect
to a microprocessor, plus two general purpose eight-bit ports and the con-
trol signals to use them. The A12 Rear Panel Assembly Data bus and Ad-
dress bus connect to the IC and have the same function as described for
the GPIB and RS-232-C controllers. The Printer Sel line is set low by the
microprocessor when it is communicating with the interface. The RD and
WR lines allow the microprocessor to either read or write to the registers in
the programmable peripheral interface IC. This IC must be initialized by the
microprocessor for Port A to be a strobed input port. Port C provides the
control signals.

The A13 Mother board provides the interconnection for the microprocessor
signals and the -i-5 V power among the following boards:

■ A14 I/O board

■ A15 Memory Management Unit (MMU) board

■ A1 7 Executive Processor board

■ A1 8 Memory board

11801C Service Manual

3-17

Block Diagram Descriptions

A14 Input/Output
(I/O) Board

The A14 I/O board contains the following circuits:

■ Data buffers

■ Timer configuration circuitry

■ Real time clock

■ Serial data interface (SDI)

■ Temp/tone readback buffer

■ Tone generator

■ GPIB control circuitry

See Figure 9-8 for a block diagram of this board.

The A14 I/O board is an interface between the Executive Processor (EXP)
and devices on the A9, A10, and A1 1 Front Panel boards, the A12 Rear
Panel assembly, and on-board I/O devices. The EXP reads and writes to
these I/O devices at specific I/O addresses. These I/O addresses are de-
coded to produce device select signals which enable the addressed device.
Each I/O device is located on I/O address boundaries of at least 100/,ex-

The lower eight bits of the Executive data bus transmit data to and from the
various I/O devices. Note that only one I/O device can be accessed at a
time.

I/O Data Buffer

This circuit buffers the lower eight bits of the Executive data bus from P105.
The output of the I/O data bus drives data to the following six on-board
devices:

■ I/O delayed data buffer

■ Rear panel data buffer

■ Front panel data buffer

■ Tone generator

■ Tone/temp readback buffer

■ Timer configuration circuitry

I/O Delayed Data Buffer

This circuitry interfaces between the I/O data bus and the Write Delayed
data bus.

3-18

Theory of Operation

Block Diagram Descriptions

Timer Configuration

This circuitry is composed of a latch and three two-input data multiplexers
built with discrete gates. When a byte of data on the I/O data bus is latched,
some of the data bits individually configure counters 1 and 2, allowing the
timer to accept different inputs for different system tasks. The operating
system uses counter 0 as a real-time clock based on the 2 MHz CLK input
from the clock generator, which is always operating at 8 MHz.

Real Time Clock

This clock and its oscillator circuit maintain the current time of day. The EXP
sets the real time clock and also interrupts the Executive processor (EXP)
every one second to request the EXP to read the time.

Serial Data Interface (SDI)

This circuitry is a custom IC that interfaces the EXP to both front panel
knobs. The EXP controls this IC, and this IC interrupts the EXP when a
device requires service.

Tone Generator

This circuitry utilizes a DAC and a timer. The timer is equipped with a special
current switch and capacitor to set the timer’s frequency. The timer outputs
a square wave whose frequency is inversely proportional to the digital value
written to the temp/tone DAC. Thus, if a zero value is input to the DAC, the
tone generator produces the highest tone.

Temp/Tone Readback Buffer

This circuit is an eight-line buffer connected to the I/O data bus. The EXP
uses this buffer to monitor the tone generator.

11 801 C Service Manual

3-19

Block Diagram Descriptions

A15 Memory
Management (MMU)
Board

The A15 MMU board consists of the following circuits:

■ MMU 1C

■ Waveform RAM

■ Display interface

■ Time Base/Controller interface

■ Executive processor (EXP) interface

■ Display 1C

■ Microprocessor

■ Bit map RAM

■ Waveform display RAM circuitry

■ Video DAC

The A15 MMU board coordinates communications among the following
three oscilloscope subsystems:

■ Display

■ Time Base/Controller

■ Executive

See Figure 9-9 for a block diagram of this board.

MMU 1C

This circuit controls all data transfers to and from waveform RAM. The MMU
gate array controls high-speed transfers of waveform data and communica-
tion messages between waveform RAM and the three subsystem interfaces:
the Display, Time Base/Controller, and Executive processors. A set of hand-
shaking lines designed to the DMA facilities of each particular subsystem
coordinates each subsystem interface.

Waveform RAM

This memory consists of 512 Kbytes of RAM. The RAM holds waveform data
and messages that are read and written by the Time Base/Controller, Dis-
play, and Executive subsystems.

Display Interface

Data is transferred to and from the Display subsystem and to and from the
MMU 1C through the Display Interface. The data is buffered with the bidirec-
tional display data buffers.

3-20

Theory of Operation

Block Diagram Descriptions

Time Base/Controller Interface

Data is transferred to and from the Time Base/Controller subsystem and to
and from the MMU 1C through this interface.

Executive Processor (EXP) Interface

This circuit consists of bidirectional buffers, address mapping programmable
array logic (PAL), and interface timing control PALs. This circuitry directs
data flow to the EXP from the MMU 1C and vice versa.

Display 1C

This component consists of the following functional circuits:

■ CRT controller

■ Video output circuitry

■ Compressor circuit

The basic function of the CRT Controller is to produce VIDEO and SYNC
signals that indicate to the CRT where to position video information. The
controller is virtually automatic in operation and invisible to the firmware
programmer except for several internal registers that must be initialized at
power-on.

The video output circuitry is where the hardware recognizes and displays
specific data structures while the raster-scan CRT displays the contents of
the bit map.

During the refresh of the screen, the hardware acquires bit map data along
with waveform display data to yield a final color index.

The compressor circuit receives a waveform composed of several possible
numbers of data points and outputs 512 pairs (one minimum and one
maximum) to the display.

Microprocessor

The microprocessor transforms the entire Display subsystem into an intelli-
gent peripheral dedicated to operating the display. The firmware that con-
trols the Display subsystem executes from ROM in the microprocessor’s
address space. The clock for this microprocessor operates at a frequency of
8 MHz.

Bit Map RAM

This memory consists of 256 Kbytes of RAM, divided into 4-bit planes of
65,536 bytes each. Three of the bit planes are for text and the remaining bit
plane is for XY, variable persistence, and infinite persistence. Each bit in a
plane represents a single pixel of the display. Setting the representative pixel
bit in each of the planes controls the color or intensity.

11801C Service Manual

3-21

Block Diagram Descriptions

Waveform Display RAM

This memory consists of 65,536 bytes. These bytes contain the minimum/
maximum pairs of values, color index, and overrange/underrange informa-
tion.

Video Digital-to-Analog Convertor (DAC)

This circuitry converts the digital data from the Display 1C into analog data
for the A7 CRT Socket board.

A1 7 Executive
Processor Board

See Figure 9-1 0 for a block diagram of this board.

Executive Processor (EXP)

This microprocessor executes firmware routines stored in EPROMS that are
located on the A1 8 Memory board to control the operation of the oscillo-
scope. Along with the numeric coprocessor, the EXP does all data proces-
sing not directly related to generating the display or digitizing the waveform.
When power is first applied to the oscilloscope, the EXP executes local and
system diagnostic tests, which are located in the EPROMs on the A18
Memory board.

The EXP performs these functions with the following three main circuits:

■ the clock generator creates the timing signals and synchronized reset
signals for the microprocessor

■ the microprocessor reads and writes data, generates addresses for I/O
and memory devices, and generates status signals for the bus controller

■ the bus controller interprets the microprocessor’s status signals and
generates the necessary bus control signals for the Executive bus

Address decoders, address latches, and data buffers are all support circuits
for I/O operations.

The A1 7 Executive Processor board consists of the following circuitry:

■ Executive processor (EXP)

■ Numeric coprocessor circuitry

■ Bus buffer circuitry

■ Preset circuitry

■ Wait state circuitry

■ Interrupt controllers

■ DMA Controller

3-22

Theory of Operation

Block Diagram Descriptions

Numeric Coprocessor

This coprocessor is a high-speed floating-point processor that executes
instructions in parallel with the EXR The EXP programs and controls the
numeric coprocessor as an I/O device at addresses 0F8/,ex to 0FF/,gx-

Bus Controller

This circuit consists of a data buffer, an address buffer, and a control buffer
that provide command and control signals from the microprocessor to the
three Executive buses. The Executive buses consist of the following:

The system data bus — is a bidirectional bus. It allows the microprocessor
to fetch instructions from memory, and also to write data to memory and
read data from memory. The memory that the microprocessor uses is lo-
cated on the A18 Memory board.

The system address bus — carries the address of a device when the
microprocessor is requesting access to that device. Once the microproces-
sor has access, the addressed device can then respond to the microproces-
sor.

The system control bus — carries control signals sent by the microproces-
sor. These control signals are sent to the devices that the microprocessor
addresses so that the devices can respond at the proper moment in the bus
cycle.

Reset

This circuitry generates synchronized ready and reset control signals.

Walt State

This circuitry extends the bus cycle so that slower devices have sufficient
time to read or write data.

Interrupt Controllers

These circuits constantly monitor the EXP’s interrupt lines to ensure that the
highest priority interrupt gets serviced first. The Interrupt controllers provide
the ability to assign priority levels to all the system’s interrupt lines and,
conversely, to ignore (mask) any of the interrupt lines as well.

DMA Controller

This circuitry shortens the GPIB transfer time and also the transmission time
of waveforms through the GPIB.

11 801 C Service Manual

3-23

Block Diagram Descriptions

A1 8 M6rnorv Board Memory Board provides the Executive processor (EXP) with system

RAM (SRAM), Nonvolatile RAM (NVRAM), and EPROM for most operations.
Support circuitry for the memories and diagnostic circuitry for troubleshoot-
ing are located on-board. All accesses to SRAM, NVRAM, or EPROMs are
initiated by the A17 Executive Processor board (specifically by the EXP or
the DMA controller). Refer to the discussion of the At 7 Executive Processor
board, earlier in this section, for bus cycle timing information.

The A1 8 Memory board consists of the following circuitry:

■ Address latches

■ Address decode and memory select circuitry

■ EPROM and system RAM

■ Memory data buffers

■ Wait state generator

■ Wait state diagnostics

■ Memory configuration readback

■ Nonvolatile RAM and battery backup

See Figure 9-1 1 for a block diagram of this board.

Address Latches

This circuitry buffers and holds the address lines for the EPROMs, SRAMs,
NVRAMs, and other on-board devices until the end of the bus cycle.

Address Decode and Memory Select

This circuitry consists of a programmable array logic (PAL) device that
decodes the address lines to produce five RAM select signals (DCS4-8) and
four EPROM select signals (DCSO-3). DCS8 enables the SRAM while
DCS4-7 enable the NVRAM. All EPROM and RAM select lines are latched,
and the latch outputs are normally enabled. While the latch enable signal is
high, the latch outputs are responsive to changes on the inputs; while the
latch enable signal is low, the select lines are latched.

The EXP on the A17 Executive Processor board generates the address line
inputs, A1 4-A1 9. Depending upon the position of a jumper on the A1 7
Executive Processor board, address lines A20-A23 can be memory bank-se-
lect lines or microprocessor address lines.

The memory select circuitry provides latched memory select lines and an
enable signal for the memory data buffers.

3-24

Theory of Operation

Block Diagram Descriptions

EPROMs, SRAM, and NVRAM

The memory includes EPROMs, System RAM (SRAM), and Nonvolatile RAM
(NVRAM). The EPROMs contain all of the operating system code and diag-
nostics code for the EXP All the memories share the latched address bus.
The SRAM stores miscellaneous constants that the operating system code
uses and produces. The NVRAM contains stored settings, stored traces,
and other nonvolatile parameters. The memories are organized into high
and low-byte pairs. The address decode PAL generates latched chip-select
signals. A separate latched chip-select signal selects each of these pair. The
memory data buffers buffer the data lines to the Executive data bus.

Memory Data Buffers

These ICs drive data between the memories and Executive data bus. Both
eight-bit buffers are enabled when all of their inputs are high.

Wait State Generator

This circuit allows the EXP to access memory devices when the EXP is
operating at faster clock frequencies. When the EXP is operating at frequen-
cies greater than 8 MHz, the bus cycle time is too short to allow reads or
writes to the present memory devices. The wait state generator sets the
SRDY line (see Figure 9-10) on the Executive bus low to signal the EXP to
lengthen the bus cycles.

The wait state generator also contains a circuit to generate control signals
(similar to those on the Executive bus). These control signals are early
address latch (ELATCH), early memory write control (EMWTC), and early
memory read control (EMRDC).

Wait State Diagnostics

This firmware routine measures the time interval that the wait state generator
generates when a one (1) is written to I/O address 8020^ex- This causes the
wait state diagnostics to connect the SRDY signal to the DIAGNSIG line on
the Executive bus. A timer on the A14 I/O board can then measure the
length of the wait.

Memory Configuration Readback

This circuitry allows the diagnostics to read the position of the memory
configuration straps and the bank address lines. One bit of the readback
data byte also indicates if the battery is at 2.5 V (an early warning of a low
battery). The EXP performs an I/O read at address 8040/,gx to read this
information.

Battery Backup

These batteries provide standby power to the nonvolatile RAM (NVRAM)
during the powered-off periods of the oscilloscope.

11801C Service Manual

3-25

Block Diagram Descriptions

A19 Strobe/TDR
Buffer Board

The A19 Strobe/TDR buffer board is comprised of the following three main
circuits:

■ Strobe sense select circuitry

■ Strobe deskew circuitry

■ TDR buffer and level shift circuitry

See Figure 9-1 2 for a block diagram of this board.

Strobe Sense Select

This circuit consists of five signal diodes (these diodes are normally off). The
diodes carry the four sampling signals (J1 A, J2A, J3A, J4A) from the four
sampling heads, and the reference strobe signal. When a particular diode is
biased on, it allows the selected strobe sense signal to continue out of
jumper J32.

Strobe Deskew

This circuit corrects the time delay between the sampling strobe signals
which may occur from the mismatch in the external cabling or in the internal
cables that distribute the strobe. The repositioning is done with the strobe
deskew voltages, which are DC control voltages found on jumper J34.
(Power is also supplied to this board through this jumper.) The strobe des-
kew voltages are generated on the A1 M/F Strobe Drive board and are
controlled by the microprocessor on the A5 Time Base/Controller board. The
sampling strobe alignment is checked by routing the strobe sense signals to
the A5 Time Base/Controller board where the microprocessor measures and
adjusts the time alignment of each sampling head.

TDR Buffer and Level Shift

This circuitry consists of an ECL buffer and four dual-transistors that level-
shift the TDR signal for proper drive of the TDR step generators in the sam-
pling heads.

A20-23 Head
Interconnect Boards

The A20-A23 Head Interconnect boards provide the interface between the
sampling head connectors (J11, J12, J13, J14), the ribbon cable W150, and
the coaxial cables W100 and W200. W150 connects to the A26 M/F Acquisi-
tion Interface board and carries the control status and power. W100 and
W200 connect to the A24/A27 Acquisition Analog board and carry the sig-
nals from the sampling heads.

3-26

Theory of Operation

Block Diagram Descriptions

A26 M/F Acquisition
interconnect Board

The A26 M/F Acquisition Interconnect board provides and distributes the
power to the interconnections between the following boards:

■ A24/A27 Acquisition Analog board

■ A25/A28 Acquisition MPU board

■ A20-A23 Head Interconnect boards

See Figure 9-13 for the block diagram of this board.

The A26 M/F Acquisition Interconnect board also has a precision voltage
reference (V) to furnish the ±5 V reference required by the A24/A27 Acquisi-
tion Analog board.

A24/A27 & A25/A28
Acquisition System
Boards

The Acquisition system consists of four boards: the A24/A27 Acquisition
Analog boards and the A25/A28 Acquisition MPU boards.

The A24/A27 Acquisition Analog board consists of the following major
blocks:

■ Programmable gain amplifiers

■ A/D converters

■ Measurement hardware

■ Timing and sampling head control

The A25/A28 Acquisition Analog board consists of the following major
blocks:

■ Shared RAM

■ Tme base/controller interface

■ Microprocessor

■ Measurement hardware

■ Timing and sampling head control

See Figures 9-14 and 9-15 for the block diagrams of these boards.

Programmable Gain Amplifiers

The four sampling head outputs are multiplexed to two amplifier channels
through the input multiplexer. The microprocessor selects a sampling head
channel to be acquired and connects it to one of the amplifier channels. The
programmable gain amplifier then applies offset (Vert Pos) and amplifies or
attenuates the signal (Vert Size). The output of the amplifier is applied to the
analog to digital (A/D) converter for conversion to digitized data.

11801C Service Manual

3-27

Block Diagram Descriptions

A/D Convertors

The output of each programmable gain amplifier is applied to an eight-bit
flash A/D converter. The converter compares its analog input to two refer-
ence voltages (-1-1 V REF and -1 V REF) and outputs an eight-bit binary
number that indicates the relative value of the analog input signal in relation
to the reference voltages. The digital output from the A/D converters is
stored in the shared RAM and made available for transfer to the Waveform
Memory through the Time Base/Controller.

Measurement Hardware

This circuitry has the selected sampling head output from the input multi-
plexer applied to a precision strobed voltage comparator. This voltage
comparator compares the sampling head output voltage to a reference
voltage generated by a 14-blt digital-to-analog converter (DAC). The
comparator output is then filtered by a filter and transition counter circuit on
the A25/A28 Acquisition MPU board to remove false transitions generated by
noise and to count the transitions.

When the processor requests a hardware timing measurement such as a
propagation delay measurement, the comparator is programmed for the
appropriate measurement level and the transition counter is programmed to
locate the selected transition number and slope. The hardware counts the
strobe pulses that occur from the beginning of the acquisition to the point
where the selected transition occurs. This operation is performed on two
channels — one for each crossing point of the timing measurement. When
the transition points are found, the Acquisition processor reads the sample
number from the hardware and stores it in a specific location in the shared
memory for the Time Base/Controller. The Time Base/Controller reads these
points (from each channel involved in the measurement), subtracts these
points, and then multiplies the result by the sampling interval. The result is a
measurement of the time between two threshold points.

Timing and Sampiing Head Controi

This hardware generates analog control voltages that control several sam-
pling head operation and calibration parameters. For example, the loop gain
calibration adjustment is controlled by an analog voltage generated in the
oscilloscope for each sampling head channel. In addition, three digital
control lines go to each sampling head — two to enable or disable TDR on
each channel and one to enable smoothing for both channels in a head.

This circuit block also generates timing signals that control when waveform
data is digitized and when the measurement hardware is clocked. The time
base sends a strobe pulse to the acquisition system and to the sampling
head to initiate a sample. Each acquisition processor can also generate
strobe pulses locally for Self-Tests and diagnostic purposes.

3-28

Theory of Operation

Block Diagram Descriptions

Shared RAM

The memory for the A25/A28 Acquisition MPU board contains 16 Kbytes of
shared RAM. This memory is arbitrated on the A25/A28 Acquisition MPU
boards between the Acquisition system processor, the Time Base/Controller
processor, and the A/D converters on the A24/A27 Acquisition Analog
board. All waveform data acquired by the Acquisition system, as well as
control and data messages passed between the Acquisition system and the
Time Base/Controller, pass through this shared memory.

Time Base/Controller Interface

This circuitry handles requests from the Time Base/Controller to access the
shared memory on the A25/A28 Acquisition MPU boards. The shared
memory is then arbitrated and buffered through the Time Base/Controller
interface hardware. This hardware decodes and latches the Time Base/Con-
troller address and generates a wait signal that holds the Time Base/Control-
ler processor in a wait state until a bus cycle can be granted to allow the
memory access to complete.

The arbitration logic coordinates requests for access to the shared memory
from the A/D converters, the Acquisition system processor, and the Time
Base/Controller processor.

Microprocessor

The microprocessor controls the Acquisition system, which has 64 Kbytes of
EPROM for code storage, 16 Kbytes of shared RAM and 8 Kbytes of un-
shared RAM. The microprocessor calibrates and manages the program-
mable gain amplifiers and measurement hardware. The microprocessor also
accepts and executes commands from the Time Base/Controller processor
and manages the sampling head digital and analog controls, including
scanning the front panel SELECT buttons on the sampling head and driving
the front panel LEDs.

11 801 C Service Manual

3-29

Block Diagram Descriptions

3-30

Theory of Operation

Performance Verification

This section contains procedures to check electrical specifications and
examine measurement limits listed in Table 4-1 . Use these procedures to
check the oscilloscope operation following repair. To functionally test the
oscilloscope, simply perform the procedures listed in Table 4-1 which have a
“yes” indication in the Functional Test column. The Specifications or Mea-
surement Limits are given at the beginning of each procedure. Adjustment
procedures are included in the Adjustment section. Refer to the 11801C
Digital Sampling Oscilloscope User Manual for more information about
oscilloscope specifications and operation. The Setup in each procedure
provides information concerning test equipment setup or interconnection.
Refer to Table 4-2 for more information concerning test equipment used in
the setups.

Most Performance Verification and Adjustment procedures can be run in any
order. However, the Sampling Head Calibration must always precede other
procedures which use an operational sampling head (i.e., does not apply to
parts using the Calibration Head). Also, if a different sampling head is used,
then a sampling head calibration is required for each additional sampling
head.

Table 4-1: Measurement Limits, Specifications, and Functional Tests

Part and Description

Measurement
Limits (Examine)

Specifications

(Check)

Functional

Test

Power-On Diagnostics

none

yes

Sampling Head

none

yes

Extended Diagnostics

none

yes

Vertical Reference Voltage

none

-1-5 V ±200 pV and
-5 V ±200 pV

Horizontal Reference Clock

none

200,000 kHz ±5 kHz

Vertical Accuracy

Vertical Gain

none

±1.0% full scale

yes

Offset Accuracy

none

±2 mV

yes

Vertical Linearity

none

±1%

System Vertical RMS Noise

200 pV at 2 mV/div
500 pV at 5 mV/div
1 mV at 10 mV/div
632 pV at 20 mV/div
1 .58 mV at 500 mV/div
3.16 mV at 100 mV/div
6.32 mV at 200 mV/div

none

yes

11801C Service Manual

4-1

Performance Verification

Table 4-1 : Measurement Limits, Specifications, and Functionai Tests (Cont.)

Part and Description

Measurement
Limits (Examine)

Specifications

(Check)

Functional

Test

Sweep Rate Accuracy

0.05% at 2 ns/div
0.08% at 1 ns/div
0.8% at 100 ps/div
2.5% at 10 ps/div
10% at 1 ps/div

none

yes

Triggering

yes

300 MHz Sensitivity

100 mVp.pat300 MHz

1 00 mV stable display

1000 MHz Sensitivity

100 mVp.pat 1000 MHz

100 mV stable display

3.0 GHz Sensitivity

100 mVp_p at 3.0 GHz

100 mV stable display

Internal Clock

yes

Rise Time

<2.5 ns

Frequency

100 kHz ±3%

Duty Cycle

50% ±3%

Prescaler

800 mVp_p at 2 GHz

800 mV stable display

yes

600 mVp_p at 3 GHz

600 mV stable display

600 mVp.p at 10 GHz

600 mV stable display

Calibrator Output

yes

Rise Time (typical)

250 ps

Peak-to-peak Amplitude

250 mV ±10%

4-2

Performance Verification

Test Equipment

Table 4-2 (Test Equipment), contains suggested test equipment for use in
this section. Procedure steps are based on the test equipment examples
given, but you may substitute other equipment with similar specifications.
The use of different equipment may alter test results, setup information, and
related connectors and adapters.

Table 4-2: Test Equipment

Description

Minimum

Specification

Examples of Applicable
Test Equipment

High Frequency
Sine Wave Genera-
tor

10 MHz to 10 GHz

WILTRON 6759B Opt 2

Sampling Head

SD-Series

SD-24 and any other Tektronix
SD-Series Sampling Head ex-
cept SD-14

Digital Voltmeter
(w/test leads)

<0.005% Accuracy

FLUKE 8842A Digital Voltmeter

Frequency Counter

One Part in
1 ,000,000 Accuracy

Tektronix DC 5010 Universal
Counter/Timer with a
TM 5000-Series Power Module

Calibration Head

Tektronix Calibration Head
067-1413-00

Precision Voltage
Source

DATA PRECISION 8200

Test Terminal

any GPIB
(IEEE- 1978) con-
troller, or ASCII
terminal equipped
with an RS-232-C
port.

Requires compat-
ible RS-232-C serial
interface cable

IBM compatible PC with termi-
nal emulation software

Coaxial Cable, 50 Q
(3 required)

50 Q, 36-inch, male
BNC connectors

Tektronix Part 012-0482-00

Coaxial Cable, RF

RF cable, 12 in.,
SMA connectors

Tektronix Part 174-1364-00

RF cable, 8.5 in.,
SMA connectors

Tektronix Part 174-1120-00

11801C Service Manual

4-3

Performance Verification

Table 4-2: Test Equipment (Cent.)

Description

Minimum

Specification

Examples of Applicable
Test Equipment

Adapters

BNC female-to-male
Dual Banana

Tektronix Part 103-0090-00

BNC male-to-female
Dual Banana

Tektronix Part 103-0035-00

SMA male-to-BNC
female (8 required)

Tektronix Part 015-1018-00

SMA female-to-BNC
male

Tektronix Part 013-0126-00

SMA male-to-N
male

Tektronix Part 015-0369-00

Power Divider, 50 Q

6 dB load isolation,
50 Q, SMA
connectors

Tektronix Part 015-1014-00

Termination, 50 Q

Impedance, 50 Q;
accuracy within 2%;
SMA connectors

Tektronix Part 015-1022-00

Attenuator, 10X

20 dB attenuation,
50 Q, one male and
one female

Tektronix Part 01 1 -0059-02

Attenuator, 2X

50 Q, SMA, one
male and one
female

Tektronix Part 015-1001 -00

Power Supplies
Troubleshooting
Fixture

Tektronix 067-1264-00
Extended Diagnostics
1 1000-Series Power Supplies
troubleshooting fixture

Probe, 10X

Attenuation 1 0X

Tektronix P6106A

Pickoff, 10X

Picosecond Pulse Labs 5520A

Power Meter

HP 436A

Power Sensor

HP 8485A

Alignment Tool

Plastic hex

Tektronix Part 003-0301 -00

Insulated slot

Tektronix Part 003-0675-01

Square Tip
(ceramic)

Tektronix Part 003-1400-00

Magnetic Screw-
driver

Holder for Torx
head tips

Tektronix Part 003-0293-00

4-4

Performance Verification

Table 4-2: Test Equipment (Cent.)

Description

Minimum

Specification

Examples of Applicable
Test Equipment

Torx Head Screw-
driver

#10 tip

Tektronix Part 003-0814-00

#15 tip

Tektronix Part 003-0966-00

#20 tip

Tektronix Part 003-0866-00

External Loopback
Connector

RS-232-C

connector

Tektronix Part 013-0198-00

Shorting Strap

two alligator clips
on a short pigtail
conductor

Integrated Circuit
Extracting Tool

1C Insertion-Extrac-
tion Pliers, 28-pin
type

General Tool P/N U505BG or
equivalent

Board Removal
Tools

Straight-slot screw-
driver, large

Torx-drive screw-
driver.

T-7, T-8, T-10, T-15,
T-20, T-25

Allen (hex) Wrench,
1/1 6-inch

Nutdrivers,
3/16-inch, 1/4-inch,
7/16-inch

Needle-nose pliers

Small Ruler

half inch rulings

Antistatic wrist strap

Tektronix Part 006-3415-04

11801C Service Manual

4-5

Performance Verification

Test Record

Photocopy the next four pages and use them to record the performance test
results for your instrument.

4-6

Performance Verification

1 1 801 C Test Record

ln?;tn impnt Rprial Niimhpr-

nprtifinatp Niimhpr-

Temperature:

RH %:

Date of Calibration:

Technician:

Performance Test

Minimum incoming Outgoing

Maximum

Vertical Accuracy

Vertical Gain, First Compartment Acquisition Measurement: ± 1 .2% at checkpoint

Channel 1

5 mV/div

-20.5 mV

-19.5 mV

10 mV/d iv

-41.0 mV

-39.0 mV

20 mV/div

-82 mV

-78 mV

50 mV/div

-205 mV

-195 mV

100 mV/div

-410 mV

-390 mV

200 mV/div

-820 mV

-780 mV

5 mV/div

19.5 mV

20.5 mV

10 mV/d iv

39.0 mV

41.0 mV

20 mV/div

78 mV

82 mV

50 mV/div

195 mV

205 mV

100 mV/div

390 mV

410 mV

200 mV/div

780 mV

820 mV

11801C Service Manual

4-7

Performance Verification

1 1 801 C Test Record (Cont.)

Performance Test

Minimum

incoming Outgoing

Maximum

Vertical Gain

1 , First Compartment Acquisition Measurement:

± 1 .2% at checkpoint

Channel 2

Step 1 1 .

5 mV/div

-20.5 mV

-19.5 mV

10 mV/d iv

-41.0 mV

-39.0 mV

20 mV/div

-82 mV

-78 mV

50 mV/div

-205 mV

-195 mV

100 mV/div

-410 mV

-390 mV

200 mV/div

-820 mV

-780 mV

5 mV/div

19.5 mV

20.5 mV

10 mV/d iv

39.0 mV

41.0 mV

20 mV/div

78 mV

82 mV

50 mV/div

195 mV

205 mV

100 mV/div

390 mV

410 mV

200 mV/div

780 mV

820 mV

Vertical Offset Accuracy, First Compartment

±2 mV

Step 10.

400 mV

398 mV

402 mV

Step 1 1 .

1 V

0.998 V

1 .002 V

2 V

1 .998 V

2.002 V

-400 mV

-402 mV

-398 mV

-1 V

-1.002 V

-0.998 V

-2 V

-2.002 V

-1.998 V

4-8

Performance Verification

1 1 801 C Test Record (Cont.)

Performance Test

Minimum

Incoming

Outgoing

Maximum

Vertical Gain

1 , Third Compartment Acquisition Measurement:

± 1 .2% at checkpoint

Channel 1

Step 1 1 .

5 mV/div

-20.5 mV

-19.5 mV

10 mV/d iv

-41.0 mV

-39.0 mV

20 mV/div

-82 mV

-78 mV

50 mV/div

-205 mV

-195 mV

100 mV/div

-410 mV

-390 mV

200 mV/div

-820 mV

-780 mV

5 mV/div

19.5 mV

20.5 mV

10 mV/d iv

39.0 mV

41.0 mV

20 mV/div

78 mV

82 mV

50 mV/div

195 mV

205 mV

100 mV/div

390 mV

410 mV

200 mV/div

780 mV

820 mV

Vertical Gain, Third Compartment Acquisition Measurement:

± 1 .2% at checkpoint

Channel 2

Step 1 1 .

5 mV/div

-20.5 mV

-19.5 mV

10 mV/d iv

-41.0 mV

-39.0 mV

20 mV/div

-82 mV

-78 mV

50 mV/div

-205 mV

-195 mV

100 mV/div

-410 mV

-390 mV

200 mV/div

-820 mV

-780 mV

5 mV/div

19.5 mV

20.5 mV

10 mV/d iv

39.0 mV

41.0 mV

20 mV/div

78 mV

82 mV

50 mV/div

195 mV

205 mV

100 mV/div

390 mV

410 mV

200 mV/div

780 mV

820 mV

11801C Service Manual

4-9

Performance Verification

1 1 801 C Test Record (Cont.)

Performance Test

Minimum incoming

Outgoing

Maximum

Vertical Offset Accuracy, Third Compartment

±2 mV

Step 10.

400 mV

398 mV

402 mV

Step 1 1 .

1 V

0.998 V

1 .002 V

2 V

1 .998 V

2.002 V

-400 mV

-402 mV

-398 mV

-1 V

-1.002 V

-0.998 V

-2 V

-2.002 V

-1.998 V

Sweep Rate Accuracy

ns Sweep Rate Accuracy

Step 10.

2 ns/div (±0.05%)

18.172 ns

18.192 ns

Step 14.

1 ns/div (±0.08%)

9.083 ns

9.098 ns

ps Sweep Rate Accuracy

Step 18.

100 ps/div (±0.8%)

902 ps

916 ps

Step 28.

10 ps/div (±2.5%)

248.1 mV

260.5 mV

Step 40.

1 ps/div (±10%)

23.1 mV

28.3 mV

Internal Clock

Step 6.
Step 8.

Rise Time
Frequency
Duty Cycle

97 kHz
47%

2.5 ns
103 kHz
53%

Calibrator Output

Step 6.

Rise Time

=250 ps

Amplitude

225 mV

275 mV

4-10

Performance Verification

Using These
Procedures

Some procedures begin with a setup illustration that shows what test equip-
ment is needed and how to connect it. The other procedures require only a
calibrated SD-Series Sampling Head. Refer to Table 4-2 (Test Equipment),
on the preceding pages for an example of the test equipment for each
procedure.

Conventions in this Manuai

In these procedures, the following conventions are used:

■ CAPITAL letters within the body of text identify front panel controls,
indicators, and connectors on the oscilloscope (for example, MEASURE)
and sampling head.

■ Bold letters identify menu labels and display messages.

■ Initial Capital letters identify connectors, controls, and indicators (for
example. On) on associated test equipment.

■ In some steps, the first word is italicized to identify a step that contains a
performance verification and an adjustment instruction. For example, if
Check is the first word in the title of a step, an electrical specification is
checked. U Adjust appears in the title, the step involves an electrical
adjustment. If Examine is the first word in the title, the step concerns
measurement limits that indicate whether the oscilloscope is operating
properly; these limits are not to be interpreted as electrical specifica-
tions.

Menu Selections and Measurement Techniques

Details on measurement techniques and instructions for making menu
selections are generally not included in these procedures. Comprehensive
descriptions of menus and oscilloscope features are located in the 1 1801C
Digital Sampling Oscilloscope User Manual.

User Manual

The 11 801 C Digital Sampling Oscilloscope User Manual is strongly recom-
mended to familiarize the first-time user with oscilloscope controls and
features.

11 801 C Service Manual

4-11

Performance Verification

4-12

Performance Verification

Performance Tests

This section contains the procedures to check the electrical specifications
and examine the measurement limits listed in Table 4-1 . To functionally test
the oscilloscope, simply perform the procedures which have a “yes” indica-
tion in the Functional column. The Specifications or Measurement Limits are
given at the beginning of each procedure. Adjustment procedures are
included in the Adjustment section. Refer to the 1 1801C Digital Oscilloscope
User Manual for more information about oscilloscope operation. The Setup
in each procedure provides information concerning test equipment setup or
interconnection. Refer to Table 4-2 for more information concerning test
equipment used in the setups.

11 801 C Service Manual

4-13

Performance Tests

Power-On

Diagnostics

This procedure should be performed within the ambient temperature range
of +18° C to +28° C (+64° F to +82° F), when a performance check at
peak operating conditions is required.

Setup to Invoke Power-On Diagnostics

11801C

SD-series
sampling
head

(not

installed

yet)

Procedure to Invoke Power-On Diagnostics

Applying a voltage outside the range printed on the sampling head
can result in damage. Static electricity is also a hazard.

The input diodes used in the sampling heads are very susceptible to dam-
age from overdrive signal or DC voltages and from electrostatic discharge.
Never apply a voltage outside the range printed on the front of the sampling
head. Operate the 11 801 C only in a static-controlled environment.

Connect the wrist strap provided with the 1 1 801 C to the ANTISTATIC CON-
NECTION, as shown in Figure 2-1 . Refer to the 1 1801C Digital Sampling
Oscilloscope User Manual tor more information.

I I Stepi: Check that the sampling head is not yet installed, and that the
ON/STANDBY switch is in the STANDBY position.

I I Step 2: Remove the top and bottom covers from the oscilloscope
(unless you are only performing a functional test).

I I Step 3: Install an SD Series sampling head in the left sampling head
compartment marked CH 1/CH 2.

I I Step 4: With the oscilloscope’s rear panel PRINCIPAL POWER SWITCH
set to OFF, connect the oscilloscope to a suitable power source.

4-14

Performance Verification

Performance Tests

□ Step 5: Set the rear panel PRINCIPAL POWER SWITCH to ON and then
set the oscilloscope’s front panel ON/STANDBY switch to ON.

When the oscilloscope is first installed, the rear panel PRINCIPAL POW-
ER SWITCH should be set to and left in the ON position. From then on,
use the front panel ON/STANDBY switch to perform all subsequent
power switching.

I I Step 6: Monitor the following diagnostic run functions, and note the
range of possible results.

Diagnostics

Each time the front panel ON/STANDBY switch is set to ON, the oscilloscope
performs Kernel diagnostics on its microprocessor subsystems, followed by
Self-Test diagnostics on most all of its major circuits. Failures from either of
these two sets of diagnostics may cause the oscilloscope to enter the Ex-
tended Diagnostics menu as described later in this section.

When Kernel diagnostics begin, the Diagnostics in Progress and Comm
Test in Progress messages are displayed on the screen. If the oscilloscope
is being powered-on from a cold condition, then the diagnostics may be
completed before the CRT is warmed up and able to display these mes-
sages. Diagnostic routines are then performed in parallel on each of the
oscilloscope’s microprocessor subsystems (Display, Executive, Time Base,
and Mainframe Acquisition). Following successful execution of their Kernel
diagnostics. Acquisition microprocessors attempt to communicate with the
Time Base microprocessor and the Time Base and Display microprocessors
attempt to communicate with the Executive microprocessor.

Successful completion of Kernel diagnostics is indicated by the start of
Self-Test diagnostics. A failure of Kernel diagnostics will be indicated by the
message, Dsy Kernel Failure, or Comm Test in Progress displaying on the
screen (for Display kernel failures) and/or by a single high-low beep and
illuminated menu button indicators (for Executive kernel failures).

Self-Test Diagnostics

These begin by displaying Self-Test in Progress (when the Display micropro-
cessor has successfully communicated with the Executive microprocessor).
Pattern changes on the display and the flashing of the display indicate a test
in progress. The Self-Test diagnostics are successfully completed when the
oscilloscope returns to normal operation. Any failures cause the oscilloscope
to produce a double high-low beep, and then to display the Extended Diag-
nostics menu on the screen. Faulty field replaceable units (FRUs) may then
be identified by touching the (?)Help label. If any errors occur, record the
error codes for the failed circuit block(s), and then refer the oscilloscope to a
qualified service person.

11801C Service Manual

4-15

Performance Tests

Front panel controls are active during the Self-Test diagnostic sequence;
however, any disturbance of these controls causes a test failure. If such a
failure occurs, the oscilloscope automatically enters the Extended Diagnos-
tics mode and displays the Extended Diagnostics menu. Touch the Exit
label twice to remove this menu. Note that if the diagnostics detect a fatal
fault, it may not be possible to exit the menu.

Power-On Diagnostics Compiete

This state is signified when the oscilloscope returns to normal operation. If
the oscilloscope passes Power-on diagnostics, the front-panel settings that
were in effect at the last power-off are restored.

4-16

Performance Verification

Performance Tests

Sampling Heads

This procedure shows the setup and lists the steps for calibrating Loop Gain
and Offset Null. Note that this is an optional enhanced accuracy procedure
that fine tunes internal channel processing circuitry in conjunction with any
operational sampling head type being used (the 067-1413-00 calibration
head is a service device and does not require system calibration). This
procedure also initiates a built-in 1 1801 C program which causes the main-
frame to remember which sampling head type was used in the calibration. In
this way, pre-calibrated heads can be interchanged without requiring recal-
ibration.

Setup to Calibrate a Sampling Head

11801C

Sampling Head (except SD-1 4)

J--- (!al I

][

t]f° ^r°][|.

□

(not connected yet) n / 12" RF Cable
50 n Termination

(not connected yet)

Procedure to Calibrate a Sampling Head

I I Step 1 : Power-up and Initialize as follows:

Set the ON/STANDBY switch to ON rocker / press

UTILITY button press

Initialize (in major menu) touch

Initialize (verify) touch

I I Step 2: Set up first Automatic Calibration as follows:

Press the UTILITY button press

Page to Enhanced Accuracy press

Gain (in major menu) touch

Identify Mainframe touch

Identify Channel (2) touch

Automatic Calibrate (in pop-up menu) touch

11801C Service Manual

4-17

Performance Tests

I I Step 3: Perform the Loop Gain calibration as follows:

Connect the CALIBRATOR output to the sampling head input to be
calibrated (2).

Select Proceed (in the Loop Gain pop-up menu) touch

Store Constants (in pop-up menu) touch

□ Step 4: Set up second Automatic Calibration as follows:

Disconnect the calibration cable from the sampling head input.

Offset (in major menu) touch

Automatic Calibrate (in pop-up menu) touch

I I Step 5: Perform the Offset Null calibration as follows:

Connect a 50 Q termination to the sampling head input.

Select Proceed (in pop-up menu) touch

Store Constants (in pop-up menu) touch

Exit (in pop-up menu) touch

r~| Step 6: Repeat Steps 1 through 5 for all sampling head compartments
and channels being tested.

4-18

Performance Verification

Performance Tests

Extended

Diagnostics

The Extended Diagnostics perform more extensive testing than the Self-Test
diagnostics. They can be used to assist troubleshooting, particularly in
service environments.

Setup to Invoke Extended Diagnostics

11801C

If the oscilloscope entered the normal operating mode without any diagnos-
tic failures, perform the following steps to enter the Extended Diagnostics
mode. No inputs or I/O cables should be attached to the oscilloscope for
these tests.

Procedure to Invoke Extended Diagnostics

□ Step 1: With the sampling head installed as illustrated, check initial
conditions as follows:

Set the oscilloscope ON/STANDBY switch to ON press

Check sampling head Select button is OFF . . visually check indicator

You may lose stored settings, stored traces, or other data stored in
NVRAM by turning the power off (that is, setting the ON/STANDBY
switch to STANDBY or the PRINCIPAL POWER SWITCH to OFF)
during the execution of the Extended Diagnostic tests that deal with
the Executive processor’s NVRAM tests. However, this does not
seriously affect oscilloscope operation.

Select the UTILITY button press

Page to Enhanced Accuracy (in major menu) touch

Page to Utility2 (in major menu) touch

Extended Diagnostic (in major menu) touch

Extended Diagnostic (in pop-up menu) touch

Select Aii, and then Run to start the tests touch

11801C Service Manual

4-19

Performance Tests

I I Step 2: C/7ec/f that all tests have executed and have a Pass status.
Then, make the following selections in the order shown:

Executive (if not already highlighted) touch

Block (in major menu) touch

External I/O (in pop-up menu) touch

Area (in major menu) touch

GPIB (in major menu) touch

Routine (in major menu) touch

I I Step 3: Select and run the following tests:

Select Run to start the Intrpt Reset test touch

Select Reset Status, and then Run to start the test touch

Select Data Lines, and then Run to start the test touch

Select Interrupt, and then Run to start the test touch

I I Step 4: Check that all four of the previous tests have executed and
passed. Then, exit as follows:

Select Exit twice to exit Extended Diagnostics touch

4-20

Performance Verification

Performance Tests

Vertical Reference
Voltage

This procedure checks that the vertical reference voltage is at ±5 V at J63C
on the A26 M/F Acquisition Interconnect board (see Figure 4-1).

This procedure should only be performed if maintenance is required.
This procedure is not necessary for verifying instrument specifica-
tions.

Specifications

The measured voltage must be within the limits of 5 V ±200 pV and -5 V
±200 pV.

Setup to Check Verticai Reference Voitage

11801C

Procedure to Check Verticai Reference Voitage

I I Step 1 : Initialize the oscilloscope settings as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

I I Step 2: Connect the Digital Voltmeter to the ±5 V reference point and
GND on the A26 Mainframe (M/F) Acquisition Interconnect board. See
Figure 4-1.

□ Step 3: Set the Voltmeter for DC Voltage, and check for a reading of
±5 V ±200 pV.

I I Step 4: Connect the Digital Voltmeter to the -5 V reference point and
GND on the A26 M/F Acquisition Interconnect board.

11801C Service Manual

4-21

Performance Tests

I I Step 5: Set the Voltmeter for DC Voltage, and check for a reading of
-5 V ±200 |jV

If the readings noted in Steps 3 and 5 are outside the stated limits,
then servicing of the oscilloscope is required before continuing to
the Horizontal Reference Clock procedure.

Figure 4-1 : A26 M/F Acquisition interconnect Board Test Point Locations

4-22

Performance Verification

Performance Tests

Horizontal
Reference Clock

This procedure verifies the correct operation and accuracy of the oscillo-
scope’s horizontal reference clock (see Figure 4-2).

This procedure should only be performed if maintenance is required.
This procedure is not necessary for verifying instrument specifica-
tions.

Specifications

The operational frequency specification for the horizontal reference clock is
200,000 kHz, ±5 kHz.

Setup to Check Horizontai Reference Ciock

11801C

Procedure to Check Horizontai Reference Ciock

I I Step 1 : Initialize the oscilloscope settings as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

I I Step 2: Perform the following 1 1 801 C operations in the order listed:

■ Set the front panel ON/STANDBY switch to STANDBY.

■ Set the oscilloscope on its right side (as viewed from facing the front
of the oscilloscope).

■ Set the oscilloscope front panel ON/STANDBY switch to ON.

11801C Service Manual

4-23

Performance Tests

r~l Step 3: Set the Frequency Counter controls/output as follows:

Frequency counter

Mode

Trigger

Slope

Attenuation . . .
Termination . .

Frequency A

. + (positive)

1 MQ

I I Step 4: At U191 on the A5 Time Base/Controller board, touch the 10X
Probe to pin 9 and the ground probe to pin 1 .

I I Step 5: Check that the frequency counter reads within the limits of
199,995 kHz and 200,005 kHz.

Figure 4-2: A5 Time Base/Controiier Board Test Point Locations

4-24

Performance Verification

Performance Tests

Vertical Accuracy

This procedure shows the setups and lists the steps to check the vertical
accuracy of the oscilloscope.

Setup to Check Vertical Gain

Procedure to Check Vertical Gain

r~| Step1: Install a Calibration Head (067-1413-00) into the position
shown in the setup diagram (CH 1/CH 2 slot). If the unit is in Standby
mode, set the power switch to ON. Set the Precision Voltage Source to
0 V and connect it to Channel 2 of the Calibration Head.

NOTE

If powering up from a cold start, the diagnostics will report an error
using the Calibration Head. The report will indicate a Time Base
error. To clear this, exit the diagnostics. Then, ignore the subse-
quent time base calibration failure notice and continue with the
following steps.

I I Step 2: Initialize the mainframe as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

r~l Step 3: Trigger the oscilloscope as follows:

TRIGGER button press

Source (in major menu) touch

Internal Clock (in pop-up menu) touch

11801C Service Manual

4-25

Performance Tests

I I Step 4: Identify the trace as follows:

Def Tra icon touch

Identify Channel (2) touch

Select Enter Desc touch

I I steps: Set the mainframe Vert Offset as follows:

Vert size icon touch

Set Vert Size:M2 to 2 mV/div adjust upper knob

r~| Step 6: Set Averaging as follows:

Acquire Desc (in major menu) touch

Average N (in pop-up menu) touch

I I Step 7: Select the Mean Measurement as follows:

MEASURE button press

Measurements (in major menu) touch

Mean (in the Measurements pop-up menu) touch

Compare & References (in major menu) touch

Save Current Meas Values as References

(in pop-up menu) touch

Compare off (to on in pop-up menu) touch

r~l Step 8: Set the Voltage source to 8 mV

Select Remove/Clr Trace (in major menu) touch

Select Clear Trace (in pop-up menu) touch

I I Step 9: Wait for averaging to complete. Then, check that the AMean
value is to be within 7.8 mV (lower spec) and 8.2 mV (upper spec).

NOTE

Averaging will complete faster if you exit the measurement menu
and then return when averaging is complete. Alternatively, use the
dial to move the Main Size setting two notches higher than the
default setting.

I I Step 10: Change the polarity of the voltage differential coming from the
precision voltage Source. Check that the AMean value is between
-7.8 mV and -8.2 mV.

4-26

Performance Verification

Performance Tests

I I Step 11: Refer to Table 4-3 and check actual results against the table
specifications for the setting levels indicated.

NOTE

Specifications are one percent of fuii scaie at each voits/ctiv setting.
Example: at 5 mV/div full scale for 10 div is 50 mV, which gives an
upper and lower spec tolerance of +0.5 mV and -0.5 mV.

Table 4-3: Voltage Source Settings

Sens.

Source V

Lower Spec

Upper Spec

5 mV/div

-20 mV

-20.5 mV

-19.5 mV

10 mV/div

-40 mV

-41.0 mV

-39.0 mV

20 mV/div

-80 mV

-82 mV

-78 mV

50 mV/div

-200 mV

-205 mV

-195 mV

100 mV/div

-400 mV

-410 mV

-390 mV

200 mV/div

-800 mV

-820 mV

-780 mV

5 mV/div

20 mV

19.5 mV

20.5 mV

10 mV/div

40 mV

39.0 mV

41.0 mV

20 mV/div

80 mV

78 mV

82 mV

50 mV/div

200 mV

195 mV

205 mV

100 mV/div

400 mV

390 mV

410 mV

200 mV/div

800 mV

780 mV

820 mV

NOTE

Up to now, you have been working with trace 1 (Channel 2), and
internal mainframe acquisition measurement channel 1. Use the
following steps to verify the vertical accuracy through internal
acquisition measurement channel 2, using trace 2. (Don’t remove
Voltage Source from Calibration Head Channel 2.)

I I Step 12: Initialize the mainframe as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

r~| Step 13: Trigger the oscilloscope as follows:

TRIGGER button press

Source (in major menu) touch

Internal Clock (in pop-up menu) touch

11801C Service Manual

4-27

Performance Tests

I I Step 14; Define the first trace as follows:

Def Tra icon touch

Identify Channel (1) touch

Select Enter Desc touch

Note that Trace 1 has been selected at the base of the screen (just
above Ml Main).

I I Step 15: Define the second trace as follows:

Def Tra icon touch

Identify Channel (2) touch

Select Enter Desc touch

Note that Trace 2 has now been selected at the base of the screen
(just above M2 Main).

r~l Step 16: Repeat Steps 5 through 12.

r~l Step 17: Power down the oscilloscope. Repeat Steps 1 through 16 for
sampling head compartment 3.

Setup to Check Offset Accuracy

Procedure to Check Offset Accuracy

r~| Stepi: This second vertical accuracy test uses the same setup prelimi-
naries as the previous test. The Calibration Head/Time Base error will
only reappear if you have activated power-up diagnostics. If so, exit
diagnostics and, in either case, continue from here.

□ Step 2: Initialize the mainframe as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

4-28

Performance Verification

Performance Tests

r~l Step 3: Trigger the oscilloscope as follows:

TRIGGER button press

Source (in major menu) touch

Internal Clock (in pop-up menu) touch

I I Step 4: Define the trace as follows:

Def Tra icon touch

Identify Channel (2) touch

Select Enter Desc touch

r~| Step 5: Set Averaging as follows:

Acquire Desc (in major menu) touch

Average N (in pop-up menu) touch

Select Exit touch

I I Step 6: Select the Mean Measurement as follows:

MEASURE Button press

Measurements (in major menu) touch

Mean (in pop-up menu) touch

Compare & Reference (in major menu) touch

Save Current Meas Values as References

(in pop-up menu) touch

Compare off (changes to on / in pop-up menu) touch

Select Exit touch

I I Step 7: Set the Vertical Size and Offset as follows:

Vertical size icon touch

Adjust the Vert Size: M2 to 10 mV/div adjust upper knob

Vert Offset: M2 (in major menu) touch

Key in 400 mV (400m) on the pop-up display touch

Select Enter touch

Check that 400 mV has now entered into the display below Vert Offset:
M2.

I I Step 8: Connect the Voltage Source to the DIRECT input of the Calibra-
tion Head.

r~l Step 9: Adjust the Voltage Source to 400 mV.

I I Step 10: Wait for averaging to complete. Then, check that AMean value
is between -2 mV and -1-2 mV.

I I Step 1 1 : Repeat Steps 2 through 1 0 for the offset values shown in
Table 4-4.

I I Step 12: Power down the oscilloscope. Repeat Steps 1 through 1 1 for
sampling head compartment 3.

11801C Service Manual

4-29

Performance Tests

Table 4-4: Vertical Offset Test Values

Sens.

Source V/
Vert Offset

Lower Spec

Upper Spec

10 mV/div

1 V

0.998 V

1 .002 V

10 mV/div

2 V

1 .998 V

2.002 V

10 mV/div

-400 mV

-402 mV

-398 mV

10 mV/div

-1 V

-1.002 V

-0.998 V

10 mV/div

-2 V

-2.002 V

-1.998 V

4-30

Performance Verification

Performance Tests

System Vertical
RMS Noise

This procedure uses the RMS measurement function to measure the noise
on the trace from a sampling head compartment.

Setup to Examine Vertical RMS Noise

Calibration Head

11801C I

Procedure to Examine Vertical RMS Noise

I I Step 1: Install the Calibration Head (067-1413-00) into the position
shown in the setup diagram. If the unit was in standby mode, set the
ON/STANDBY switch to ON.

NOTE

If powering up from a cold start, The diagnostics will report an error
using the Calibration Head. The report will indicate a Time Base
error. To clear this, exit the diagnostics. Then, ignore the subse-
quent time base calibration failure notice and continue with the
following steps.

I I Step 2: Initialize the mainframe as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

r~| Step 3: Trigger the oscilloscope as follows:

TRIGGER button press

Source (in major menu) touch

Internal Clock (in pop-up menu) touch

I I Step 4: Identify the trace as follows:

Def Tra icon touch

Identify Channel (1) touch

Select Enter Desc touch

11801C Service Manual

4-31

Performance Tests

I I steps: Set the mainframe Vert Size as follows:

Vert Size icon touch

Set Vert Size:M1 to 2 mV/div adjust upper knob

r~| Step 6: Set the record length as follows:

Horizontal Desc (in major menu) touch

Main Record Length (in pop-up menu) touch

Set Main Record Len to 5120 points adjust upper knob

r~| Step 7: Store the trace as follows:

STORE/RECALL button press

Store Trace (in major menu) touch

Trace 1 (in pop-up menu) touch

Note that you must touch Trace 1 even though it is highlighted in
the menu.

Recail Trace (in major menu) touch

STO 1 (in pop-up menu) touch

I I Step 8: Measure the Mean value as follows:

MEASURE button press

Measurements (in major menu) touch

Mean (in pop-up menu) touch

Exit Menu (in pop-up menu) touch

NOTE

Record (write down) the mean value for use in the next step.

□ Step 9: Define the trace to be stored as follows:

Def Tra icon touch

Stored Traces (in pop-up menu) touch

Stored 1 (in pop-up menu) touch

Enter ST01 - (mean value) touch

Use pop-up key pad to enter ST01 - (mean value) recorded
(written down) in Step 8.

4-32

Performance Verification

Performance Tests

NOTE

For example, if mean value is 50.2 pV, you would key in
“-(50.2 EEX - 6)”. ST01 already appears on upper left of display.
Exponents are entered by pressing the EEX key, followed by the
sign of the exponent (if negative), followed by the exponent value.

Enter Desc (in pop-up menu) touch

I I Step 10: Measure the RMS value as follows:

MEASURE button press

Measurements (in major menu) touch

RMS (in pop-up menu) touch

Check that RMS is <200 pV.

Exit Menu (to exit) touch

I I Step 1 1 : Erase the test traces as follows:

STORE/RECALL button press

Delete Trace (in major menu) touch

All Traces (in pop-up menu) touch

Delete Selected Traces (in pop-up menu) touch

I I Step 12: Repeat Steps 4 through 1 1 at the sensitivities listed in

Table 4-5, and check the resulting RMS against the matching specifica-
tion value in the table.

Table 4-5: Sensitivity Settings

Sensitivity

Specification

5 mV/div

500 pV

10 mV/div

1 mV

20 mV/div

632 pV

50 mV/div

1 .58 mV

100 mV/div

3.16 mV

200 mV/div

6.32 mV

r~l Step 13: Power down the oscilloscope. Repeat Steps 1 through 12 for
all sampling head compartments.

11801C Service Manual

4-33

Performance Tests

Sweep Rate Accuracy

This procedure shows the setups and lists the steps to check the Sweep
Rate Accuracy.

Setup to Examine Sweep Rate Accuracy

CH 1 SD-24

Procedure to Examine Sweep Rate Accuracy

□ Step 1 : Install the SD-24 Sampling Head into the compartment shown
in the setup diagram (CH 1/CH 2 slot). If the unit is in standby mode, set

the ON/STANDBY switch to ON.

I I Step 2: Initialize the mainframe as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

I I Step 3: Set the horizontal record length as follows:

Horizontal Desc (in major menu) touch

Main Record Length (in pop-up menu) touch

Set Main Record Len to 1024 points adjust upper knob

I I Step 4: Identify the trace as follows:

Def Tra icon touch

Identify Mainframe touch

Identify Channel (1) touch

Select Enter Desc touch

4-34

Performance Verification

Performance Tests

r~l Step 5: Engage high precision calibration mode as follows:

UTILITY button press

Page to Enhanced Accuracy touch

Time Base Cal Mode (in major menu) touch

High Prec (in pop-up menu) touch

Exit (in pop-up menu) touch

Sweep Rate Accuracy 2 ns/div

r~| Step 6: Adjust the Sweep Rate to 2 ns/div.

Horizontal icon touch

Set Main Size to 2 ns/div adjust upper knob

I I Step 7: Adjust the Signal Generator to the following settings:

Frequency 55 MHz

Amplitude I.OVrms

NOTE

Check that selected Sampling Head channel (1) indicator is flash-
ing. If not, select channel (1) by pressing select button.

I I Step 8: Turn mainframe averaging on.

WAVEFORM button press

Acquire Desc (in major menu) touch

Average N On (in pop-up menu) touch

Select Exit (in the pop-up menu) touch

NOTE

Position the display so the sine wave is centered on the screen. To
ensure accurate period measurement, the display must be a full
cycle.

r~| Step 9: Obtain Period as follows:

MEASURE button press

Measurement (in major menu) touch

Period (in pop-up menu) touch

Exit Menu (in pop-up menu) touch

r~| Step 10: Examine that the period is between 18.172 ns and 18.192 ns,

showing that sweep rate accuracy is within 0.05%.

11801C Service Manual

4-35

Performance Tests

Sweep Rate Accuracy 1 ns/div

r~| Step 11: Adjust the Sweep Rate to 1 ns/div.

Horizontal ( ^ ) icon touch

Set Main Size to 1 ns/div adjust upper knob

I I Step 12: >4c//(7sf the Signal Generator to the following settings:

Frequency 110 MHz

Amplitude I.OVrms

□ Step 13: Press the UTILITY button and adjust the lower knob for a
display showing a full waveform.

I I Step 14: Press the MEASURE button and check for a period interval
between 9.083 ns and 9.098 ns, showing that sweep rate accuracy is
within 0.08%.

Sweep Rate Accuracy 100 ps/div

r~l Step 15: Use the upper control knob to adjust the Main Size to 100 ps/
div.

I I Step 16: Ac//t/sf the Signal Generator to the following settings:

Frequency 1.1 GHz

Amplitude 2.0 Vp.p (1 .4 Vrms)

(Set for 1 .000 V ±0.004 Vp.p on screen.)

□ Step 17: Press the UTILITY button and adjust the lower knob for a
display showing a full waveform.

□ Step 18: Press the MEASURE button and check for a period interval
between 902 ps and 916 ps, showing that sweep rate accuracy is with-
in 0.8%.

Sweep Rate Accuracy 10 ps/div

I I Step 19: Ac//usf the Signal Generator to the following settings:

Frequency 800 MHz

Amplitude 2.0 Vp.p (1 .4 Vrms)

(Set for 1 .000 V ±0.004 Vp.p on screen.)

I I Step 20: Invoke smoothing as follows:

WAVEFORM button press

Sampling Head Fnc’s (in major menu) touch

Smoothing On (in pop-up menu) touch

Exit (in pop-up menu) touch

r~| Step 21: Ac//usf the Main Size to 130 ps/div.

4-36

Performance Verification

Performance Tests

r~| Step 22: Adjust the Main Pos to 55 ns.

r~| Step 23: Set the Main Pos control (lower knob) so that the zero cross-
ing of the waveform occurs on the center graticule.

I I Step 24: Set the horizontal reference point to Center as follows, so that
the waveform will be expanded about the horizontal center:

WAVEFORM button press

Horizontal Desc (in major menu) touch

Center (in pop-up menu) touch

I I Step 25: Adjust the Vertical Size as follows:

Vertical icon touch

Set Vert Size to 50 mV adjust upper knob

I I Step 26: Adjust the Main Size as follows:

Horizontal icon touch

Set the Main Size to 10 ps/div adjust upper knob

I I Step 27: Activate the cursors as follows:

Cursors icon touch

I I Step 28: Read the Av located in the major menu. Av should be within
-260.5 mV and -248.1 mV or -1-248.1 mV and -1-260.5 mV, showing
that the sweep rate accuracy is within 2.5%.

I I Step 29: Touch Exit (in the major menu).

Sweep Rate Accuracy 1 ps/div

I I Step 30: Ac//usf the Signal Generator to the following settings:

Frequency 800 MHz

Amplitude 2.0 Vp.p (1 .4 Vrms)

(Set for 1 .000 V ±0.004 Vp.p on screen.)

□ Step 31 : Invoke smoothing as follows:

WAVEFORM button press

Sampling Head Fnc’s (in major menu) touch

Smoothing On (in pop-up menu) touch

Exit (in pop-up menu) touch

r~| Step 32: Adjust the Main Size to 130 ps/div.
r~| Step 33: Adjust the Main Pos to 55 ns.

I I Step 34: Set the Main Pos control (lower knob) so that the zero cross-
ing of the waveform occurs on the center graticule.

11801C Service Manual

4-37

Performance Tests

I I Step 35: Set the horizontal reference point to Center as follows, so that
the waveform will be expanded around the horizontal center:

WAVEFORM button press

Horizontal Desc (in major menu) touch

Center (in pop-up menu) touch

I I Step 36: Adjust the Vertical Size as follows:

Vertical icon touch

Set Vert Size to 5 mV adjust upper knob

I I Step 37: Set the Main Size as follows:

Horizontal icon touch

Set Main Size to 1 ps/div adjust upper knob

□ Step 38: Turn mainframe averaging on.

WAVEFORM button press

Acquire Desc (in major menu) touch

Average N (in pop-up menu) touch

Select Exit (in pop-up menu) touch

I I Step 39: Activate the cursors as follows:

Cursors icon touch

I I Step 40: Read the Av located in the major menu. Av should be within
-28.3 mV and -23.1 mV, or within -I-32.1 mV and -1-28.3 mV, showing
that the sweep rate accuracy is within 20%.

I I Step 41: Touch Exit (in the major menu).

4-38

Performance Verification

Performance Tests

Triggering,
Externai Direct

This procedure verifies the correct operation and accuracy of the oscillo-
scope’s trigger system.

Specifications

The specifications for triggering using the external trigger are as follows:

■ 1 00 mVp.p at 300 MHz

■ 100 mVp.pat 1000 MHz

■ 1 00 mVp.p at 3.0 GHz

Setup to Check Triggering

SD-24

Sampling

Head Qj-j 7 2X Attenuators

Procedure to Check Triggering

I I Step 1 : Install the SD-24 Sampling Head into the position shown in the
setup diagram (CH 1/CH 2 slot). If the unit was in standby mode, set the
ON/STANDBY switch to ON.

I I Step 2: Initialize the mainframe as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

r~l Step 3: Adjust the high frequency generator as follows:

400 mVp.p at 300 MHz

I I Step 4: On the Sampling Head, press the Channel 1 select button.

II8OIC Service Manual

4-39

Performance Tests

I I Step 5: Make the following selections:

AUTOSET button press

Slightly adjust the Trigger Levei (in TRIGGER major menu) if
necessary.

MEASURE button press

Measurement (in major menu) touch

Peak-Peak (in pop-up menu) touch

WAVEFORM button press

Sampling Head Fnc’s

(in major menu) touch

Smoothing On (in pop-up menu) touch

Exit (in pop-up menu) touch

□ Step 6: Check waveform for stable triggering. Using AUTOSET, repeat
procedure for the following frequency generator settings:

400mVp.p at 1000 MHz
400 mVp.p at 3.0 GHz

4-40

Performance Verification

Performance Tests

Pr©SCal6r Triggsring procedure verifies the correct operation and accuracy of the 1 1801C’s

Prescaler trigger system.

Specifications

The specifications for Prescaler triggering are as follows:

■ 800 mVp.p at 2 GHz

■ 600 mVp.p at 3 GHz

■ 600 mVp.p at 1 0 GHz

Setup to Check Prescaier Triggering

Procedure to Check Prescaier Triggering

I I Step 1 : Install the SD-24 Sampling Head into the CH 1/CH 2 slot of the
mainframe. Set the ON/STANDBY switch to ON and let the instrument
warm up for approximately 15 minutes. Initialize the mainframe settings,
then perform the following settings and steps.

□ Step 2: Connect the High Frequency Generator to the Picosecond
Pulse Labs (PSPL) 10X Pick-off IN. Connect the PSPL-^ 10 output to
Channel 1 of the Sampling Head.

11801C Service Manual

4-41

Performance Tests

I I Step 3: Connect the PSPL X1 output to the power meter/sensor (meter/
sensor must be calibrated). Set the Generator frequency to 2 GHz.

Adjust the Generator output until the power meter reads:

2.0 dBm (800 mVp.p). Use correction factors for the sensor.

I I Step 4: Connect the PSPL XI output to the 1 1801 C Prescaler Trigger
input.

I I Step 5: 1 1 801 C mainframe settings:

DefTra touch

Select Channel 1 , Ml touch

TRIGGER button press

Source touch

External Prescaler touch

Exit touch

Horizontal ( ^ ) icon touch

Adjust Main Size to 200 ps/div adjust upper knob

Vertical ( | ) icon touch

Adjust Main Size to 10 mV/div adjust upper knob

I I Step 6: Turn AVG ON. C/?ecA' display for stable triggering. Then turn the

AVG OFF.

r~l Step 7: Repeat steps 3, 4, 5 and 6 for the following settings:

Table 4-6: Prescaler Test Settings

Generator Freq

Power Reading

Main Size

Vert Size

3 GHz

-0.458 dBm

(600 mVp.p)

50 ps/div

10 mV/d iv

10 GHz

-0.458 dBm

(600 mVp.p)

50 ps/div

10 mV/d iv

4-42

Performance Verification

Performance Tests

Internal Clock

This procedure verifies the correct operation and accuracy of the oscillo-
scope’s Internal Clock signal.

Measurement Limits

The measurement limits of the internal clock pulse are as follows:

■ rise time <2.5 ns

■ frequency of 100 kHz ±3% accuracy

■ duty cycle 50% ±3%

Setup to Examine Internai Ciock

CH 1

Procedure to Examine internai Ciock

I I Step 1 : Install the SD-24 Sampling Head into the position shown in the
setup diagram (CH 1/CH 2 slot). If the unit was in standby mode, set the

ON/STANDBY switch to ON.

I I Step 2: Initialize the mainframe as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

r~l Step 3: Trigger the oscilloscope as follows:

TRIGGER Button press

Source (in pop-up menu) Internal Clock

I I Step 4: On the Sampling Head, press the Channel 1 select button.
□ Step 5: On the oscilloscope, press the AUTOSET button.

11801C Service Manual

4-43

Performance Tests

I I Step 6: Check the rise time as follows:

MEASURE button press

Measurements (in the major menu) touch

Rise (in the pop-up menu) touch

Check that Rise is <2.5 ns.

Exit Menu (in pop-up menu) touch

r~l Step 7: Change the sweep rate as follows:

Horizontal ( ^ ) icon touch

Adjust Main Size to 5 ps/div adjust upper knob

r~| steps: Check the frequency as follows:

MEASURE button press

Measurements (in major menu) touch

Frequency (in pop-up menu) touch

Duty Cycle (in pop-up menu) touch

Check XhaX the frequency is between 97 kHz and 103 kHz.

Check that the Duty Cycle is between 47% and 53%.

Exit Menu (in pop-up menu) touch

4-44

Performance Verification

Performance Tests

Calibrator Output

This procedure verifies the correct operation and accuracy of the oscillo-
scope’s calibrator.

Measurement Limits

The measurement limits of the calibrator output are as follows:

■ amplitude 250 mV ±15%

■ rise time =250 ps

Setup to Examine Caiibrator Output

CH 1

Procedure to Examine Caiibrator

I I Step 1 : Install the SD-24 Sampling Head into the position shown in the
setup diagram (CH 1/CH 2 slot). If the unit was in standby mode, set the

ON/STANDBY switch to ON.

I I Step 2: Initialize the mainframe as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

r~l Step 3: Trigger the oscilloscope as follows:

TRIGGER Button press

Source (in pop-up menu) Internal Clock

□ Step 4: On the Sampling Head, press the Channel 1 select button.
r~| Step 5: On the oscilloscope, press the AUTOSET button.

11801C Service Manual

4-45

Performance Tests

r~l Step 6: Check the peak-to-peak amplitude as follows:

MEASURE button press

Measurements (in the major menu) touch

Peak-Peak (in the pop-up menu) touch

Rise (in the pop-up menu) touch

Rise (in the major menu) touch

Proximai (in the pop-up menu) touch

Check XhaX peak-to-peak amplitude is between 212.5 mV and
287.5 mV (250 mV ±15%).

Adjust Proximai for 20% and Distal for 80%.

Check that rise time is approximately 250 ps.

4-46

Performance Verification

Adjustments

This section contains procedures to check electrical specifications, to ex-
amine measurement limits, and to manually set all internal adjustments
listed in Table 5-1 . Use these procedures to return the oscilloscope to speci-
fied operation following repair or as part of a comprehensive performance
verification procedure to verify that the oscilloscope meets specifications. To
adjust the oscilloscope, simply perform the procedures listed in this section.
The Specifications or Measurement Limits are given at the beginning of each
procedure. Functional tests are included in the Performance Verification
section. Refer to the 1 1801C Digitai Sampiing Osciiloscope User Manuai for
more information about specifications and oscilloscope operation. The
Setup in each procedure provides information concerning test equipment
setup or interconnection. Refer to Table 5-2 for more information concerning
test equipment used in the setups.

Most Adjustment and Performance Verification procedures can be run in any
order. However, the Sampling Head Calibration must always precede other
procedures which use an operational sampling head. Also, if a different
sampling head is used, then sampling head calibration is required for each
additional sampling head.

11801C Service Manual

5-1

Adjustments

Table 5-1 :

Measurement Limits and Adjustments

Procedure Description

Measurement
Limits (Examine)

Adjustments

(Adjust)

Power Supply

Voltage Supply

+ 4.85 V to +5.25 V

none

Voltage Reference

+ 5.15 V to +5.25 V

R800 +5.2 V Ref for +5.20 V

Regulator Reference

+9.95 V to +10.05 V

R730 + 1 0 V Ref for + 1 0.00 V

Display

Cutoff

visible

SCREEN, on transformer on
A8 CRT Driver board, until
display appears

Convergence

primary colors are not
separated in the white grid

CONVERGENCE, R210, for
optimum convergence of
red, green, and blue

Focus

focused grid pattern

FOCUS, on transformer on
A8 CRT Driver board, for
optimum focus on white grid
pattern

Vertical Size and
Position

align with tic marks

VERT SIZE, L321 , and VERT
POS, R31 1 , for optimum
alignment

Horizontal Size,
Linearity and
Position

align with tic marks and for

optimum

appearance

H-SIZE, R501, H-LIN, R502,
and H-POS, R500, for
optimum alignment and
linearity

Gray Scale

white at the top of the
display and gray at the
bottom, and the right side of
the display is cut off

SCREEN, on transformer on
A8 CRT Driver board; RED,
R200; GREEN, R201,;and
BLUE, R203; for cutoff and
color balance

Color Impurity

no severe color impurities in
red, green, and blue display

cycle power on and off

Real Time Clock

1 ,000,000 ps ±5 ps

Real Time Clock for
1 ,000,000 ps

5-2

Adjustment Procedures

Adjustments

Test Equipment

Table 5-2 (Test Equipment), contains suggested test equipment for use in
this manual. Procedure steps are based on the test equipment examples
given, but you may substitute other equipment with similar specifications.
The use of different equipment may alter test results, setup information, and
related connectors and adapters.

Table 5-2: Test Equipment

Description

Minimum

Specification

Examples of Applicable
Test Equipment

High Frequency
Sine Wave Genera-
tor

10 MHz to 10 GHz

WILTRON 6759B Opt 2

Sampling Head

SD-Series

SD-24 and any other Tektronix
SD-Series Sampling Head
except SD-14

Digital Voltmeter
(w/test leads)

<0.005% Accuracy

FLUKE 8842A Digital Voltmeter

Calibration Genera-
tor

DC output, 0.25%
accuracy 1 V output
amplitude

Tektronix PG 506 Calibration
Generator with a TM
500-Series Power Module

Frequency Counter

One Part in
1 ,000,000 Accuracy

Tektronix DC 5010 Universal
Counter/Timer with a
TM 5000-Series Power Module

Calibration Head

Tektronix Calibration Head
067-1413-00

Precision Voltage
Source

DATA PRECISION 8200

Test Terminal

any GPIB
(IEEE- 1978) con-
troller, or ASCII ter-
minal equipped with
an RS-232-C port.
Requires compat-
ible RS-232-C serial
interface cable

IBM compatible PC with termi-
nal emulation software

Coaxial Cable, 50 Q
(3 required)

50 Q, 36-inch, male
BNC connectors

Tektronix Part 012-0482-00

Coaxial Cable, RF

RF cable, 12 in.,
SMA connectors

Tektronix Part 174-1364-00

RF cable, 8.5 in.,
SMA connectors

Tektronix Part 174-1120-00

11801C Service Manual

5-3

Adjustments

Table 5-2: Test Equipment (Cent.)

Description

Minimum

Specification

Examples of Applicable
Test Equipment

Adapters

BNC female-to-male
Dual Banana

Tektronix Part 103-0090-00

BNC male-to-female
Dual Banana

Tektronix Part 103-0035-00

SMA male-to-BNC
female (8 required)

Tektronix Part 015-1018-00

SMA female-to-BNC
male

Tektronix Part 013-0126-00

SMA male-to-N
male

Tektronix Part 015-0369-00

Power Divider, 50 Q

6 dB load isolation,
50 Q, SMA connec-
tors

Tektronix Part 015-1014-00

Termination, 50 Q

Impedance, 50 Q;
accuracy within 2%;
SMA connectors

Tektronix Part 015-1022-00

Attenuator, 10X

20 dB attenuation,
50 Q, one male and
one female

Tektronix Part 01 1 -0059-02

Attenuator, 2X

50 Q, SMA, one
male and one
female

Tektronix Part 015-1001 -00

Power Supplies
Troubleshooting
Fixture

Tektronix Part 067-1264-00
Extended Diagnostics
1 1000-Series Power Supplies
troubleshooting fixture

Probe, 10X

Attenuation 1 0X

Tektronix P6106A

Alignment Tool

Plastic hex

Tektronix Part 003-0301 -00

Insulated slot

Tektronix Part 003-0675-01

Square Tip
(ceramic)

Tektronix Part 003-1400-00

Magnetic Screw-
driver

Holder for Torx
head tips

Tektronix Part 003-0293-00

Torx Head Screw-
driver

#10 tip

Tektronix Part 003-0814-00

#15 tip

Tektronix Part 003-0966-00

#20 tip

Tektronix Part 003-0866-00

5-4

Adjustment Procedures

Adjustments

Table 5-2: Test Equipment (Cent.)

Description

Minimum

Specification

Examples of Applicable
Test Equipment

External Loopback
Connector

RS-232-C connec-
tor

Tektronix Part 013-0198-00

Shorting Strap

two alligator clips
on a short pigtail
conductor

Integrated Circuit
Extracting Tool

IC Insertion-Extrac-
tion Pliers, 28-pin
type

General Tool P/N U505BG or
equivalent

Board Removal
Tools

Straight-slot screw-
driver, large

Torx-drive screw-
driver,

T-7, T-8, T-10, T-15,
T-20, T-25

Allen (hex) Wrench,
1/16-inch

Nutdrivers,
3/16-inch, 1/4-inch,
7/16-inch

Needle-nose pliers

Small Ruler

half inch rulings

Antistatic wrist strap

Tektronix Part 006-3415-04

11801C Service Manual

5-5

Adjustments

Using These
Procedures

Some procedures begin with a setup illustration that shows what test equip-
ment is needed and how to connect it. The other procedures require only a
calibrated SD-Series Sampling Head. Refer to Table 5-2 (Test Equipment),
on the preceding pages for an example of the test equipment for each
procedure.

Conventions in this Manuai

In these procedures, the following conventions are used:

■ CAPITAL letters within the body of text identify front panel controls,
indicators, and connectors on the oscilloscope (for example, MEASURE)
and sampling head.

■ Bold letters identify menu labels and display messages.

■ Initial Capital letters identify connectors, controls, and indicators (for
example. On) on associated test equipment.

Menu Selections and Measurement Techniques

User Manual

A review of the 1 1801C Digital Sampling Oscilloscope User Manual is
strongly recommended to familiarize the first-time user with oscilloscope
controls and features.

5-6

Adjustment Procedures

Adjustments

Power Supply

This procedure shows the setup and lists the steps to examine the Mea-
sured Voltage Supply and to check/adjust the Voltage Reference and the
Regulator Reference (see Figures 5-1, 5-2, and 5-3).

This procedure should only be performed if the instrument is out of
measurement limits and maintenance is required. If the oscilloscope
is already within limits, proceed to the Display procedure.

Measurement Limits

The measurement limits for this procedure are as follows:

■ Measured Voltage Supply limits must be within -t-4.85 V and -t-5.25 V

■ Voltage Reference must be within -t-5.15 V and -1-5.25 V

■ Regulator Reference must be within -1-9.95 V and -l- 1 0.05 V

Setup to Examine Voitage Suppiy

11801C

Procedure to Examine Voitage Suppiy

I I Step 1 : Set the oscilloscope ON/STANDBY switch to ON, and initialize

as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

I I Step 2: With the oscilloscope top and bottom covers removed, refer to
the Maintenance section and locate the A18 Memory board.

11 801 C Service Manual

5-7

Adjustments

I I Step 3: Connect the digital multimeter to TP200 and TP300 as indicated
in the setup illustration (see also Figure 5-1).

I I Step 4: Check that the Digital Voltmeter reads within the limits of
-I-4.85 V and -I-5.25 V.

TP200 VCC TP300 GND

Lithium Battery
(BT150)

Figure 5-1 : A18 Memory Board Test Point Locations

5-8

Adjustment Procedures

Adjustments

Setup to Examine/Adjust Voltage Reference

11801C

This procedure should only be performed if maintenance is required.
This is not necessary for verifying instrument specifications.

Procedure to Examine/Adjust Voltage Reference

I I Step1: Perform the following settings in the order listed:

a. Set the front panel ON/STANDBY switch to STANDBY and the rear
panel PRINCIPAL POWER SWITCH to OFF. Disconnect the oscillo-
scope from the power source.

b. Remove the Power Supply module following the procedure listed
under Power Supply Module Removal/Replacement in the Mainte-
nance section.

c. Create a short between test points TP830 and TP831 on the A2A2
Control Rectifier board using a shorting strap. See Figure 5-2.

d. Connect the oscilloscope Power Supply module to a suitable line
power source.

e. Set the rear panel PRINCIPAL POWER SWITCH to ON.

I I Step 2: With the Digital Voltmeter set to DC Voltage and connected as

indicated in the setup diagram, check that the multimeter reads within

the limits of -1-5.1 5 and -t-5.25 V.

DO NOT attempt to change the following -I-5.2 V Ref setting if the
reading is within the stated limits. Proceed to Step 4.

^VARNIN^

To prevent electric shock, use extreme caution when making the
following adjustment.

11801C Service Manual

5-9

Adjustments

□

Step 3: Adjust the +5.2 V Ref, R800, on the A2A2 Control Rectifier
board to +5.20 V.

Step 4: Remove the Digital Voltmeter leads from the test points.

Step 5: Set the rear panel PRINCIPAL POWER SWITCH to OFF.

Step 6: Disconnect the oscilloscope from the power source.

Step 7: Remove all test leads and the TP830/831 shorting strap.

Step 8: Replace the Power Supply module using the instructions in the
Maintenance section.

□ Step 9: Set the rear panel PRINCIPAL POWER SWITCH to ON, and the
front panel ON/STANDBY switch to ON.

R800
+5.2 V
REF

TP701

TP831

TP830

Figure 5-2: A2A2 Control Rectifier Board Test Point and Adjustment Locations

5-10

Adjustment Procedures

Adjustments

Setup to Examine/Adjust Regulator Reference

11801C

Procedure to Examine/Adjust Regulator Reference

□ Step 1 : Make the connections shown in the setup and Figure 5-3 dia-
grams. Check that the oscilloscope power is ON.

I I Step 2: With the Digital Voltmeter in DC Voltage mode, check the Volt-
meter for a reading within the limits of -t-9.95 V and -i- 10.05 V.

DO NOT attempt to make the following adjustment to R730 if the
reading is within the stated limits. Instead, proceed to Step 4.

WARNING

To prevent electric shock, use extreme caution when making the
following adjustment. Access the test points from the right side of
the oscilloscope.

I I Step 3: Adjust the -i-IO V Ref, R730, on the A4 Regulator board to
-1-10.00 V.

I I Step 4: Remove the test leads.

I I Step 5: Initiate Power-On Diagnostics (see the Performance Verification
section).

11801C Service Manual

5-11

5-12 Adjustment Procedures

Adjustments

Display

This procedure shows the setup and lists the steps to examine/adjust the A7
CRT Socket board and the A8 CRT Driver board (see Figures 5-4 and 5-5).

The adjustments in this procedure affect only the visual aspects of
the CRT display and you should only perform these adjustments
when the CRT, A7 CRT Socket board or A8 CRT Driver board com-
ponents are replaced. These adjustments do not affect oscilloscope
accuracy since all measurements are made on the acquired data,
not the displayed data. Unless alignment or brightness difficulties
are apparent, proceed to the Real Time Clock procedure.

For all Examine steps in this procedure, if the display parameter examined is
within the stated limits, then do not perform the Adjust step following that
Examine step. Instead, proceed to the step following the Adjust step.

Measurement Limits

The measurement limits are set on the CRT as follows:

■ The display must be visible (not cut off).

■ The red, green, and blue traces must not be separated.

■ Focus is adjusted for minimum line width.

■ Vertical size is adjusted to align the corners of the grid pattern with the
tic marks on the edges of the front panel bezel.

■ Horizontal size is adjusted to align the corners of the grid pattern with
the tic marks on the top and bottom edges of the front panel bezel, and
the horizontal linearity is adjusted for uniform grid box length.

■ Horizontal linearity is adjusted for optimum appearance using an inter-
nally generated grid pattern.

■ Red, green, and blue colors must have optimum white to gray scale
linearity.

■ Red Display, Green Disply, and Blue Display in Extended Diagnostics
must not contain severe color impurities.

11801C Service Manual

5-13

Adjustments

Setup to Examine/Adjust the Display

11801C

Procedure to Examine/Adjust the Display

To prevent electric shock, use extreme caution when performing
the following adjustment.

I I Step1: Perform the following settings in the order listed:

11801C

ON/STANDBY STANDBY

I I Step 2: Remove the top and bottom cabinet panel covers.

I I Step 3: Remove the three screws that secure the CRT cover, and then
remove the cover.

I I Step 4: Remove the two screws that secure the cover that shields the
A7 CRT Socket board (CRT Socket board cover).

r~| Step 5: Set the ON/STANDBY switch to ON.

I I Step 6: Examine that the display is visible.

□ Step 7: Adjust SCREEN, located on the transformer mounted to the A8
CRT Driver board, clockwise until the display appears.

r~| steps: Press the UTILITY button.

r~| Step 9: Touch Extended Diagnostic, then touch Extended Diagnostic
in the Verify Diagnostics pop-up menu.

r~| Step 10: Touch Biock and then Front Panei.

r~| Step 1 1 : Touch Area and then Test Pattern.

r~| Step 12: Touch Routine and then White Grid.

5-14

Adjustment Procedures

Adjustments

I I Step 13: Touch Run in the major menu.

I I Step 14: Examine that the primary colors (red, green, and blue) are not
separated in the white grid pattern.

WARNING

To prevent electric shock, do not touch the back side of the A7 CRT
Socket board. Use extreme caution when performing the following
adjustment.

r~| Step 15: y4c//usf CONVERGENCE, R210, on the A7 CRT Socket board
for the optimum vertical convergence of the red, green, and blue colors.

I I Step 16: Examine that the grid pattern is focused.

I I Step 17: Adjust FOCUS, located on the transformer mounted on the A8
CRT Driver board, for the optimum focus of the white grid pattern.

I I Step 18: Examine that the grid is aligned with the top and bottom tic
marks along the inside vertical edge of the front panel bezel. To elimi-
nate any parallax error, look directly ahead at the CRT, and then align
the top of the grid with the top vertical tic mark and the bottom of the
grid with the bottom tic mark.

r~| Step 1 9: Adjust VERT SIZE, L321 , and VERT PCS, R31 1 , on the A8 CRT
Driver board to align the grid with the tic marks along the inside vertical
edge of the front panel bezel.

I I Step 20: Examine that the grid is aligned with the horizontal tic marks at
the top and bottom of the front panel bezel and that the grid boxes are
of uniform length throughout the grid pattern.

□ Step 21: Adjust H SIZE, R501 ; H LIN, R502; and H PCS, R500, on the
A8 CRT Driver board for best overall linearity and position. Use the
horizontal tic marks at the top and bottom of the front panel bezel to
align the grid.

I I Step 22: H-SIZE, H-LIN, and H-POS potentiometers interact, so you
may need to repeat Steps 20 and 21 until they are all correctly adjusted.

r~| Step 23: Touch Exit to return to the Routine menu of the Extended
Diagnostic menu structure.

r~| Step 24: Touch Gray Scaie in the Routine menu.

I I Step 25: Touch Run in the major menu.

11801C Service Manual

5-15

Adjustments

I I Step 26: Exam/ne that the color scale is white at the top, gray at the
bottom, and the background on the right side of the display is cut off
(that is, the vertical raster lines are not visible on the right side of the
display).

I I Step 27: Adjust Red, R200; Green, R201 ; and Blue, R203, on the A7
CRT Socket board fully counterclockwise.

I I Step 28: Adjust SCREEN, located on the transformer that is mounted
on the A8 CRT Driver board, so that the bottom block of the gray scale
is visible but the background on the right side of the display is still cut
off.

□ Step 29: Note which color (red, green, or blue) appears most promi-
nently in the display. DO NOT adjust this color in the following step.

□ Step 30: Adjust RED, R200; GREEN, R201 ; or BLUE, R203, on the A7
CRT Socket board for a pure white to gray scale display. Only adjust the
colors that do not appear prominent. For example, if the display appears
to be more red, then adjust the GREEN and BLUE potentiometers.

NOTE

SCREEN may have to be adjusted slightly if any of the colors are
adjusted. If the vertical raster lines are visible in the background,
then adjust SCREEN so that the background is just cut off, but the
bottom gray box is still visible.

□ Step 31: Touch Exit to return to the Extended Diagnostic menu struc-
ture.

□ Stop 32i Touch Red Displey, 3.nd thon touch Run.

I I Step 33: Examine the red display for any severe color impurities.

r~| Step 34: Touch Exit to return to the Extended Diagnostics menu
structure.

r~| Step 35: Touch Green Dispiy and then touch Run.

□ Step 36: Examine the green display for any severe color impurities.

r~| Step 37: Touch Exit to return to the Extended Diagnostic menu struc-
ture.

r~| Step 38: Touch Biue Dispiay and then touch Run.

I I Step 39: Examine the blue display for any severe color impurities.

If the gray scale meets the previous conditions, do not perform the
adjustments in Steps 27, 28, and 30. Proceed to Step 31 .

5-16

Adjustment Procedures

Adjustments

r~l Step 40: If any of the color displays (that is, the Red Display, Green
Disply, or Blue Display) showed severe color impurities, then perform
the following to restore the color purity:

■ Ensure that the oscilloscope environment is free of all external
magnetic fields. For example, a magnetic screwdriver near the
oscilloscope could cause color impurities on the screen.

■ Set the ON/STANDBY switch to STANDBY.

■ Wait 1 0 seconds, then set the ON/STANDBY switch to ON.

■ Examine the color displays again, and verify that the color impurities
are removed.

NOTE

When the oscilloscope is moved in the earth’s magnetic field, color
impurities will appear on the display. This is normal. To remove the
impurity, repeat Step 40.

□ Step 41: Set the ON/STANDBY switch to STANDBY.

I I Step 42: Replace the CRT Socket board cover and the CRT cover.

11801C Service Manual

5-17

Adjustments

FOCUS SCREEN

Figure 5-4: A8 CRT Driver Board Adjustment Locations

5-18

Adjustment Procedures

Adjustments

GREEN

R201

RED

R200

BLUE

R203

CONVERGENCE

R210

Figure 5-5: A7 CRT Socket Board Adjustment Locations

11801C Service Manual

5-19

Adjustments

Real Time Clock

This procedure verifies the correct operation and accuracy of the oscillo-
scope’s input/output systems (see Figure 5-6).

This procedure should be performed only if maintenance is required.
Its use is not necessary for verifying instrument specifications.

Measurement Limits

The measurement limit for the real time clock is 1 ,000,000 ps ±5 ps.

Setup to Examine/Adjust Reai Time Ciock

CH 1

Procedure to Examine/Adjust Reai Time Ciock

I I Step 1 : Initialize the oscilloscope settings as follows:

UTILITY button press

Initialize (in major menu) touch

Initialize (in verification pop-up menu) touch

5-20

Adjustment Procedures

Adjustments

I I Step 2: Perform the following operations in the order given:

■ Set the front panel ON/STANDBY switch to STANDBY

■ Remove the L bracket on the front of the card cage.

■ Remove both plastic retaining strips from the top of card cage.

■ Remove the A1 7 Main Processor board, and then install it in the
fourth slot from the outer edge.

■ Remove the A29 Memory Expansion board, and then install it in the
third slot.

■ Remove the A1 4 Input/Output (I/O) board, and then install it in
second slot.

■ Move the A1 8 Memory board from the first slot to the fifth slot.

■ Reconnect all the cables to the A1 4 I/O board.

■ Set the oscilloscope front panel ON/STANDBY switch to ON.

I I Step 3: Connect the Frequency Counter as indicated in the setup

diagram (see also Figure 5-6), and set the controls as follows:

Frequency counter

Mode Period

Trigger DC

Slope - (negative)

Time Base 1 MHz

I I Step 4: Make the following oscilloscope selections:

UTILITY button press

Page to Enhanced Accuracy (in major menu) touch

Page to Utility2 (in major menu) touch

Extended Diagnostics (in major menu) touch

Extended Diagnostics (in pop-up menu) touch

Block (in major menu) touch

input/Output (in pop-up menu) touch

Area (in major menu) touch

Reai Time Cik (in pop-up menu) touch

Routine (in major menu) touch

Caiibrate (in pop-up menu) touch

Run (in major menu) touch

I I steps: £xam/ne that the frequency counter reads within the limits of
999,995 ps and 1 ,000,005 ps.

DO NOT attempt to optimize the Real Time Clock setting if the
period is within the stated limits. Proceed to Step 7.

r~| Step 6: Adjust Real Time Clock, 051 0, for 1 ,000,000 ps.

11801C Service Manual

5-21

Adjustments

□

Step 7: Remove the frequency counter from the power module.

Step 8: Set the oscilloscope ON/STANDBY switch to STANDBY.

Step 9: Replace the circuit boards (rearranged in Step 1) in their origi-
nal positions.

C510

Real Time

TP31 Ground Clock

5-22

Adjustment Procedures

Preventive Maintenance

Regular maintenance can prevent instrument breakdown and may improve
the reliability of the instrument. The environment in which the instrument
operates will determine the frequency of maintenance. A convenient time for
doing preventive maintenance is prior to performing an electrical adjust-
ment.

Removing the
Cabinet Paneis

WARNING

To prevent electric shock when operating the instrument with the
covers removed, do not touch exposed connections or compo-
nents. Dangerous potentials exist at several points throughout this
instrument.

To avoid electric shock, disconnect the power before cleaning the
instrument or replacing any parts. Some transistors have voltages
present on their cases.

The top and bottom cabinet panels (or covers) protect you from operating
potentials present within the instrument. In addition, the panels reduce
radiation of electromagnetic interference from the instrument. To remove the
panels, loosen the fasteners and lift the panels off. Operate the instrument
with the panels in place to protect the interior from dust.

11 801 C Service Manual

6-1

Preventive Maintenance

Cleaning the
Instrument

The instrument should be cleaned as often as operating conditions require.
Dirt in the instrument can cause overheating and component breakdown.
Dirt on components acts as an insulating blanket and prevents efficient heat
dissipation. Dirt also provides an electrical conduction path which may
cause the instrument to fail. The side panels reduce the amount of dust that
reaches the interior of the instrument. Keep the side panels in place for
safety and cooling.

Avoid the use of chemical cleaning agents which might damage the
plastics used in this instrument. Use a nonresidue type of cleaner,
preferably isopropyl alcohol or totally denatured ethyl alcohol.
Before using any other type of cleaner, consult your local Tektronix
service center or representative.

Exterior

Dust on the instrument can be removed with a soft cloth or small brush. The
brush is also useful for dislodging dirt on and around the front panel con-
trols. Dirt which remains can be removed with a soft cloth dampened in a
mild detergent and water solution. Do not use abrasive cleaners.

CRT

Faceplates are cleaned with a soft, lint-free cloth dampened with denatured
alcohol.

6-2

Maintenance

Preventive Maintenance

Visual Inspection

Periodic Electrical
Adjustment

Interior

Cleaning should seldom be necessary. To clean the interior, blow off the
dust with dry, low-velocity air (approximately 5 Ib/in2). Remove any dirt which
remains with a soft brush or a cloth dampened with a mild detergent and
water solution. A cotton-tipped applicator is useful for cleaning in narrow
spaces, or for cleaning more delicate circuit components. After cleaning,
use a washcloth dampened with water to remove any residue.

Circuit boards and components must be dry before appiying pow-
er, to prevent damage from electricai arcing.

The high-voltage circuits should receive special attention. Exces-
sive dirt in these circuits may cause high-voltage arcing and result
in improper instrument operation.

The instrument should be inspected occasionally for defects such as broken
connections, improperly seated semiconductors, damaged or improperly
installed circuit boards, and heat-damaged parts. The corrective procedure
for most visible defects is obvious; however, particular care must be taken if
heat-damaged parts are found. Since overheating usually indicates other
trouble in the instrument, correcting the cause of overheating is important to
prevent the damage from reoccurring.

To ensure accurate measurements, check the electrical adjustment of this
instrument after each 2,000 hours of operation or every 24 months if used
infrequently.

11801C Service Manual

6-3

Preventive Maintenance

6-4

Maintenance

Corrective Maintenance

Power Supply Voltage
Hazard

Ordering Parts

Corrective maintenance consists of module and board replacement proce-
dure for repairing the instrument.

Use caution if working near any metal-faced part in the Power Supply mod-
ule.

WARNIN^

All metal components, Including any metal-faced ones, In the
Power Supply module should be considered hazardous because
these components may be at the AC line voltage potential.

Always remove the line power cord before attempting any disas-
sembly procedures.

An electric-shock hazard exists when the instrument is not
grounded. Do not remove the ground wire (green-yellow) that
connects the Power Supply module chassis to the instrument.

When ordering replacement parts from Tektronix, Inc., include the following
information:

■ instrument type

■ instrument serial number

■ a description of the part

■ Tektronix part number

11801C Service Manual

6-5

Corrective Maintenance

Static-Sensitive
Device Ciassification

Static discharge can damage any semiconductor component in this
instrument. Foilow the precautions in this section to prevent dam-
age.

This instrument contains electrical components that are susceptible to
damage from static discharge. See Table 6-1 for the relative susceptibility of
various classes of semiconductors. Static voltages of 1 kV to 30 kV are
common in unprotected environments.

Table 6-1 : Relative Susceptibility to Damage from Static Discharge

Semiconductor Classes

Relative

Susceptibility

Levels^

MOS or CMOS microcircuits, and discrete or linear
microcircuits with MOS inputs (most sensitive)

100 V to 500 V

ECL

200 V to 500 V

Schottky signal diodes

250 V

Schottky TTL

500 V

High-frequency bipolar transistors

400 V to 600 V

JFETs

600 V to 800 V

Linear microcircuits

400 V to 1000 V
(est.)

Low-power Schottky TTL

900 V

TTL (least sensitive)

1200 V

1 Voltage discharged from a 100 pF capacitor through a resistance of 100 fl

6-6

Maintenance

Corrective Maintenance

Observe the following precautions to avoid damage:

■ Minimize handling of static-sensitive components.

■ Transport and store static-sensitive components or assemblies in their
original containers, anti-static tube rail, or conductive foam. Label any
package that contains static-sensitive assemblies or components.

■ Discharge the static voltage from your body by wearing a wrist strap
while handling these components. Servicing static-sensitive assemblies
or components should be performed only at a static-free work station by
qualified service personnel. We recommend using the static control mat;
refer to Table 4-2 for the part numbers of this test equipment.

■ Keep the work station surface free of anything that can generate or hold
a static charge.

■ Keep the component leads shorted together whenever possible by
storing them in conductive foam or rails.

■ Pick up components by the body, never by the leads.

■ Do not slide the components over any surface.

■ Avoid handling components in areas that have a floor or work-surface
covering that can generate a static charge.

11801C Service Manual

6-7

Corrective Maintenance

Use Table 6-2 as a convenient reference for finding connector and screw
locations when removing and replacing field replaceable units (FRUs). The
first column in the table lists the FRU to be removed or replaced, and the
second column lists the figures that you should reference for the location of
connector and screw locations discussed in the procedure to remove/re-
place this FRU.

Table 6-2: FRU Removal/Replacement Figure Cross Reference

FRU to be Removed/
Replaced

Figures to Reference During Removal

Page

Power Supply Module

Figure 6-2

Removing the Power Supply Rear Plate, Fan Housing,
and Rear Panel Connector Plate

. .. 6-16

Figure 6-3

A2A2 Control Rectifier Board Connectors Locations ....

. .. 6-17

Fan Motor

Figure 6-2

Removing the Power Supply Rear Plate, Fan Housing,
and Rear Panel Connector Plate

. .. 6-16

Removing/Replacing the Cathode Ray Tube 6-24

Removing/Replacing the A8 CRT Driver Board 6-39

Removing/Replacing the A10 Front Panel

Button Board 6-43

Multi-Pin Connector Orientation and Semiconductor
Indexing Diagram 6-74

Acquisition Unit Figure 6-23 Removing/Replacing the A1 9 Strobe/TDR

Buffer Board

Figure 6-26 Removing/Replacing the A26 M/F Acquisition

Interconnect Board

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor
Indexing Diagram

Batteries Figure 6-1 0 Removing/Replacing the A5 Time Base/

Controller Board 6-36

Figure 6-19 Removing/Replacing the A14 I/O Board 6-50

Figure 6-22 Removing/Replacing the A18 Memory Board 6-56

A1 Mainframe (M/F) Strobe Figure 6-8 Removing/Replacing the A1 M/F Strobe Drive Board 6-31

Drive Board Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A3 Mainframe (M/F) Power Figure 6-2 Removing the Power Supply Rear Plate, Fan Housing,

Connect Board and Rear Panel Connector Plate 6-16

Figure 6-3 A2A2 Control Rectifier Board Connectors Locations 6-17

Figure 6-9 Removing/Replacing the A4 Regulator Board 6-33

Figure 6-1 0 Removing/Replacing the A5 Time Base/

Controller Board 6-36

Figure 6-19 Removing/Replacing the A14 I/O Board 6-50

Figure 6-23 Removing/Replacing the A1 9 Strobe/TDR

Buffer Board 6-58

6-58

6-61

6-74

Cathode Ray Tube (CRT) Figure 6-5

Figure 6-12
Figure 6-15

Figure 6-32

Removing and
Replacing FRUs

6-8

Maintenance

Corrective Maintenance

Table 6-2: FRU Removal/Replacement Figure Cross Reference (Cont.)

FRU to be Removed/ Figures to Reference During Removal Page

Replaced

A4 Regulator Board Figure 6-2 Removing the Power Supply Rear Plate, Fan Housing,

and Rear Panel Connector Plate 6-16

Figure 6-3 A2A2 Control Rectifier Board Connectors Locations 6-17

Figure 6-9 Removing/Replacing the A4 Regulator Board 6-33

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A5 Time Base/Controller Figure 6-10 Removing/Replacing the A5 Time Base/Controller Board

Board and A6 Calibrator Board 6-36

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A6 Calibrator Board Figure 6-10 Removing/Replacing the A5 Time Base/Controller Board

and A6 Calibrator Board (Steps 1 and 2 only) 6-36

A7 CRT Socket Board Figure 6-1 1 Removing/Replacing the A7 CRT Driver Board 6-38

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A8 CRT Driver Board Figure 6-5 Removing/Replacing the Cathode Ray Tube 6-24

Figure 6-12 Removing/Replacing the A8 CRT Driver Board 6-39

Figure 6-1 5 Removing/Replacing the A1 0 Front Panel

Button Board 6-43

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A9 Touch Panel Assembly Figure 6-5 Removing/Replacing the Cathode Ray Tube 6-24

Figure 6-1 5 Removing/Replacing the A1 0 Front Panel

Button Board 6-43

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A10 Front Panel Control Figure 6-5 Removing/Replacing the Cathode Ray Tube 6-24

Board Figure 6-1 5 Removing/Replacing the A1 0 Front Panel

Button Board 6-43

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A1 1 Front Panel Button Figure 6-5 Removing/Replacing the Cathode Ray Tube 6-24

Board Figure 6-1 5 Removing/Replacing the A1 0 Front Panel

Button Board 6-43

Figure 6-1 6 Removing/Replacing the A1 1 Front Panel

Button Board 6-44

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A1 2 Rear Panel Assembly Figure 6-5 Removing/Replacing the Cathode Ray Tube 6-24

Figure 6-17 Removing/Replacing the A12 Rear Panel Assembly 6-46

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

11801C Service Manual

6-9

Corrective Maintenance

Table 6-2: FRU Removal/Replacement Figure Cross Reference (Cont.)

FRU to be Removed/ Figures to Reference During Removal Page

Replaced

A1 3 Mother Board Figure 6-7 Top View of the Card Cage 6-30

Figure 6-18 Removing/Replacing the A13 Mother Board 6-48

Figure 6-19 Removing/Replacing the A14 I/O Board 6-50

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A1 4 Input/Output (I/O) Figure 6-7 Top View of the Card Cage 6-30

Board Figure 6-19 Removing/Replacing the A1 4 I/O Board 6-50

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A1 5 Memory Manager Unit Figure 6-7 Top View of the Card Cage 6-30

(MMU) Board Figure 6-20 Removing/Replacing the A1 5 MMU Board 6-52

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A1 7 Main Processor Board Figure 6-7 Top View of the Card Cage 6-30

Figure 6-21 Removing/Replacing the A1 7 Main

Processor Board 6-54

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A1 8 Memory Board Figure 6-7 Top View of the Card Cage 6-30

Figure 6-22 Removing/Replacing the A18 Memory Board 6-56

A1 9 Strobe/TDR Buffer Figure 6-23 Removing/Replacing the A1 9 Strobe/TDR

Board Buffer Board 6-58

Figure 6-26 Removing/Replacing the A26 M/F Acquisition

Interconnect Board 6-61

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

A20-A23 Head Interconnect Figure 6-23 Removing/Replacing the A1 9 Strobe/TDR

Boards Buffer Board 6-58

Figure 6-24 Removing/Replacing the A20-A23 Head

Interconnect Boards 6-59

Figure 6-25 Removing/Replacing the Front Subpanel Assembly 6-60

Figure 6-26 Removing/Replacing the A26 M/F Acquisition

Interconnect Board 6-61

Figure 6-28 Removing/Replacing the A24/A27 Acquisition

Analog Boards 6-63

Figure 6-29 Removing/Replacing the A25/A28 Acquisition

MPU Boards 6-64

Figure 6-32 Multi-Pin Connector Orientation and Semiconductor

Indexing Diagram 6-74

6-70

Maintenance

Corrective Maintenance

Table 6-2: FRU Removal/Replacement Figure Cross Reference (Cont.)

FRU to be Removed/ Figures to Reference During Removal Page

Replaced

A26 Mainframe (M/F) Figure 6-23 Removing/Repiacing the A1 9 Strobe/TDR

Acquisition interconnect Buffer Board 6-58

Board Figure 6-25 Removing/Repiacing the Front Subpanei Assembiy 6-60

Figure 6-26 Removing/Repiacing the A26 M/F Acquisition

interconnect Board 6-61

Figure 6-27 Top View of the A26 M/F Acquisition interconnect Board . . . 6-62

Figure 6-28 Removing/Repiacing the A24/A27 Acquisition Anaiog

Boards 6-63

Figure 6-29 Removing/Repiacing the A25/A28 Acquisition

MPU Boards 6-64

Figure 6-32 Muiti-Pin Connector Orientation and Semiconductor

indexing Diagram 6-74

A24/A27 Acquisition Anaiog Figure 6-23 Removing/Repiacing the A1 9 Strobe/TDR

Boards Buffer Board 6-58

Figure 6-26 Removing/Repiacing the A26 M/F Acquisition

interconnect Board 6-61

Figure 6-28 Removing/Repiacing the A24/A27 Acquisition Anaiog

Boards 6-63

Figure 6-32 Muiti-Pin Connector Orientation and Semiconductor

indexing Diagram 6-74

A25/A28 Acquisition MPU Figure 6-23 Removing/Repiacing the A1 9 Strobe/TDR

Boards Buffer Board 6-58

Figure 6-26 Removing/Repiacing the A26 M/F Acquisition

interconnect Board 6-61

Figure 6-29 Removing/Repiacing the A25/A28 Acquisition

MPU Boards 6-64

Figure 6-32 Muiti-Pin Connector Orientation and Semiconductor

indexing Diagram 6-74

Firmware iCs Figure 6-30 FRU iC Detaii 6-67

Figure 6-32 Muiti-Pin Connector Orientation and Semiconductor

indexing Diagram 6-74

Seriai Data interface (SDi) Figure 6-19 Removing/Repiacing the A14 i/0 Board 6-50

IC Figure 6-32 Muiti-Pin Connector Orientation and Semiconductor

indexing Diagram 6-74

Figure 6-31 iC insertion-Extraction Tooi 6-69

Fuses Figure 6-37 Fuse Locations 6-107

11801C Service Manual

6-11

Corrective Maintenance

NOTE

In addition to the figures listed in Table 6-2, the exploded-view
drawings in the Parts List section may be helpful in removing or
disassembling individual FRUs or subassemblies. Also, Figures 6-1
and 6-30 are useful for determining the location of FRUs and
FRU ICs.

The top and/or bottom covers will need to be removed for most repairs. To
loosen the cover fasteners, use a coin or a straight-slot screwdriver with a
large-sized tip and rotate the cover fasteners a quarter turn counter-clock-
wise.

Whenever a specific area is mentioned (such as the right side), it will usually
be in reference to the front of the instrument. If another reference is in-
tended, it will be indicated (for example, viewing from the left side or viewing
from the rear of the instrument).

All connector names are labeled on the circuit board and/or on the connec-
tors themselves.

WARNIN^

To avoid electric-shock hazard and instrument damage, always
disconnect the oscilloscope from its power source before remov-
ing or replacing FRUs. For sampling head removal or replacement,
switch the front panel ON/STANDBY switch to STANDBY.

6-12

Maintenance

Corrective Maintenance

Electrical Lock-on of
the Front Panel
ON/STANDBY Power
Switch

Some applications of the oscilloscope may require that the power remain
on. To electrically lock the power on, use the following procedure:

□ Step 1 : Switch the rear panel PRINCIPAL POWER SWITCH to OFF.

r~| Step 2: Remove the AC power cable.

I I Step 3: Position the instrument on its left (handle) side, as viewed from
the front.

□

Step 4: Remove the bottom cover.

Step 5: Locate the A4 Regulator board.

Step 6: Locate the J820 jumper on the A4 Regulator board.

Step 7: Reposition the J820 jumper from its two outer (right side) pins
to its two inner (left side) pins, without dropping the jumper.

I I Step 8: Replace the bottom cover. Turn the instrument in the upright
position.

r~| Step 9: Reconnect the AC power cable and switch the PRINCIPAL
POWER SWITCH to ON.

The power will now remain on regardless of the setting of the ON/
STANDBY power switch.

To prevent damage to the instrument andjor sampling head, do not
install or remove a sampling head while the power is on.

I I Step 10; To turn the power off while the ON/STANDBY power switch is
disabled, use the rear panel PRINCIPAL POWER SWITCH.

To return to normal operation of the ON/STANDBY Power Switch, follow the
preceding steps in reverse order.

11801C Service Manual

6-13

Corrective Maintenance

A25

Acquisition
MPU Board

A24

Acquisition
Anaiog Board

" A28

Acquisition MPU
vN. Board

/ A21

I Acquisition

I Anainn Qoar

Anaiog Board

A19

StrobeiTDR
Buffer Board

A26

M/F Acquisition
interconnect Board

Figure 6-1: Field Replaceable Unit (FRU) Locator (Cont.)

11801C Service Manual

6-15

Corrective Maintenance

Power Supply
Module Removal/
Replacement

The Power Supply module slides out of the rear of the oscilloscope for
maintenance and troubleshooting. It may also be removed to gain better
access to the A3 M/F Power Connect board or the A4 Regulator board.

See Figure 6-2 and Figure 6-3 for connector and screw locations.

Power Supply Rear-plate Screws (4) Fan-housing Screws (4)

Power Supply Rear-plate Screws (4)

Rear Panel Connector-plate Screws (4)

Figure 6-2: Removing the Power Suppiy Module, Fan Housing, and Rear Panel Connector Plate

6-16

Maintenance

Corrective Maintenance

J70 J81 J65

Figure 6-3; A2A2 Control Rectifier Board Connector Locations

To remove the Power Supply module from the oscilloscope, proceed as

follows:

□ Step 1 : Turn the instrument on its left side (as viewed facing the rear
panel). The Power Supply module will now be at the bottom of the
instrument.

□ Step 2: Remove the eight Torx head screws that secure the power
supply module.

□ Step 3: Carefully pull the Power Supply module partially out of the
instrument. Do not stretch taut or bind the wires attached to the A2A2
Control Rectifier board connectors.

To prevent damage to the connector pins, pull the Power Supply
module only partially out of the instrument.

11801C Service Manual

6-17

Corrective Maintenance

I I Step 4: Remove the wire connectors from the pins on the A2A2 Control
Rectifier board.

I I Step 5: Remove the chassis ground (green-yellow) wire that is con-
nected to the Power Supply module from the chassis of the instrument.

r~l Step 6: Remove the Power Supply module.

To replace the Power Supply module, perform the previous steps in the
reverse order.

NOTE

Align the metal guides on the top of the Power Supply module with
the grooves inside the upper part of the opening in the instrument.

Be careful not to pinch any wires or interconnecting cables while
installing the Power Supply module.

6-18

Maintenance

Corrective Maintenance

Fan Motor Removal/
Replacement

See Figure 6-2 for connector and screw locations.

Remove and replace the fan motor as follows:

I I Step1: Using a pencil or tape, mark the top of the fan motor housing
for later use in determining the position of the motor. Remove the four
screws securing the housing to the rear of the instrument mainframe.
Hold the housing as you remove the last screws.

I I Step 2: Separate the grill and the housing from the motor.

□ Step 3: Remove the two wires at their motor connections. Note that the
red wire is (-I-) and the brown wire is (-).

I I Step 4: Remove the fan motor.

NOTE

Observe the position in which the motor was mounted to ensure
that the motor is remounted in its originai positioning, or the fan
wires may not reach.

To replace the fan motor, perform the previous steps in the reverse order,
noting the following additional points while replacing the motor:

■ use the mark from Step 1 to determine the original position of the motor

■ tighten the screws securely

■ remove the mark from the top of the housing

■ check that no wires contact the fan blades

To prevent damage to the fan connection, be carefui not to pinch
the wires under the fan housing.

11801C Service Manual

6-19

Corrective Maintenance

Cathode Ray Tube
(CRT) Removal/
Replacement

WARNING

The cathode ray tube (CRT) may retain a dangerous electrical
(16 kV) charge. To prevent electric shock, fully discharge the anode
before removing the CRT. Short the anode lead from the CRT to the
chassis. Wait approximately ten minutes and again firmly short the
anode lead to the chassis. Then, remove the CRT

If the CRT breaks, the glass fragments scatter at a high velocity
(implosion). Use extreme care when handling the CRT. Protective
clothing and safety glasses should be worn. Avoid striking the CRT
on any object which might cause it to crack or implode. When
storing a CRT, place It In a protective carton or set the CRT face
down in a protected location with smooth surface and with the CRT
faceplate on a soft mat.

See Figures 6-1 , 6-4, 6-5, 6-6, 6-7, 6-13, and 6-32 for module, connector,

screw, and index locations.

Remove the CRT as follows:

I I Step 1 : Remove the three Torx head screws that secure the CRT cover,
and then the CRT cover.

I I Step 2: Set the instrument in the inverted position.

I I Step 3: Use a 1/1 6-inch Allen wrench to loosen the two small screws
that secure the two control knobs. Carefully remove the control so
knobs that you do not lose the small Allen screws inside the knobs.

I CAUTION I

When replacing the two control knobs, do not overtighten the two
Allen screws.

I I Step 4: Remove the two Torx head screws on the bottom of the A9
Touch Panel Assembly.

I I Step 5: Lift up on the bottom of the A9 Touch Panel Assembly and

swing the assembly outward. The top of the A9 Touch Panel Assembly is
held in place with two tabs that hook under the top of the chassis. Pull
the assembly out until you can access the black ground wire that con-
nects the A9 Touch Panel Assembly to the instrument chassis.

I I Step 6: Remove the quick-disconnect ground connector that connects
the black ground wire to the instrument chassis.

6-20

Maintenance

Corrective Maintenance

I I Step 7: Set the A9 Touch Panel Assembly aside. To avoid stressing the
ribbon cable that is still connected to the A9 Touch Panel Assembly and
to keep the assembly from cluttering your work space, place the A9
Touch Panel Assembly on top of the sampling head compartments. Do
not damage the A9 Touch Panel Assembly when placing it on top of the
sampling head plug-in compartments.

I I Step 8: Carefully set the instrument on its left side.

I I Step 9: Remove the two plastic circuit board guides from the top of the
card cage.

I I Step 1 0: Remove the two Torx head screws that secure the A7 CRT
Socket board cover. Use a short Torx head screwdriver to remove the
rear-most Torx head screw.

I I Step 1 1 : Remove the A7 CRT Socket board cover.

I I Step 12: Slowly pull the A7 CRT Socket board towards the rear of the
instrument to unplug the A7 CRT Socket board from the CRT.

NOTE

When reattaching the A 7 CRT Socket board to the CRT, align the
pins of the CRT to the receptacles on the A7 CRT Socket board.

Then, slowly push the pins into the receptacles.

Do not force the connection into place; doing so can bend or break
some of the pins. If the pins do not slide easily into the receptacles,
then pull the A7 CRT Socket board away from the CRT, and realign
the A7 CRT Socket board to the CRT.

^VARNIN^

The CRT anode voltage is 16 kV. To avoid electric shock, ground
the anode lead from the CRT to the chassis to remove any stored
charge remaining in the CRT. Wait approximately ten minutes. Then,
ground the anode load to the chassis again.

I I Step 13: Remove connector J54 from the A8 CRT Driver board. Note
the position of the multi-pin connector’s index triangle to ensure that you
can correctly replace the connector.

I I Step 14: Remove the four Torx head screws that secure the CRT to the
top of the instrument chassis. Two of the screws are removed from the
front of the front panel chassis and two of the screws are removed from
behind the front panel casting.

11801C Service Manual

6-21

Corrective Maintenance

I I Step 15: Remove the top CRT support bar from the instrument. The
CRT support bar is not attached once the four Torx head screws secur-
ing the top of the CRT are removed.

□ Step 1 6: Remove the four Torx head screws that secure the CRT to the
bottom of the instrument chassis. Two of the screws are removed from
the front of the front panel chassis, and two of the screws are removed
from behind the front panel casting.

I I Step 17: Remove the bottom CRT support bar from the instrument.

I CAUTION I

Once the four Torx head screws are removed from the bottom of
the CRT, the CRT is not attached to the instrument. Use care to not
damage the CRT white it is loose in the instrument.

I I Step 18: Slowly pull the CRT out of the front panel chassis.

To replace the CRT, perform the previous steps in reverse order.

NOTE

Replacing the CRT will require that the instrument be readjusted.

6-22

Maintenance

Corrective Maintenance

A7 CRT Socket

A7 CRT Socket Board Cover

Board Cover Tone Head Screws (2)

Figure 6-5: Removing/Replacing the Cathode Ray Tube

6-24

Maintenance

11 801 C Service Manual

6-25

Corrective Maintenance

Acquisition Unit

Removai/

Repiacement

See Figures 6-23, 6-26, and 6-32 for connector, screw, and index locations.

Remove and replace the Acquisition unit as follows (the Acquisition unit can
be removed with the instrument in the normal upright position for all steps):

Lifting the trim covers to remove them wiil break the trim covers.
There is a clip on the inside of the trim cover which slides over the
end of the side frame section. To remove the trim covers, move
each cover toward the end of the instrument where it is located.
(The front cover moves forward and the rear cover moves back-
ward.) Moving the clip about 1/8-inch wili release the cover. Then,
the cover can be removed from the instrument.

I I Step 1 : Remove the bolt from the top of the chassis, just behind the
front casting.

I I Step 2: Remove the trim covers from the right side (as viewed from the
front of the instrument).

I I Step 3: Remove the two Torx head screws that hold the frame section
and remove the frame section.

I I Step 4: Remove connectors J10 on the A26 M/F Acquisition Intercon-
nect board and J34 on the A19 Strobe/TDR Buffer board. Note the
position of the connector’s index triangles to ensure that the multi-pin
connectors can be correctly replaced.

I I Step 5: Remove connectors J29A, J30A, J32, J33A, and J33B on the
A19 Strobe/TDR Buffer board.

r~l Step 6: Grab between the two sampling head slots and gently pull out
the Acquisition unit a few inches.

I I Step 7: Remove the gray ground wire from the rear of the Acquisition
unit.

I I Step 8: Remove the Acquisition unit.

To prevent damage to interconnecting wires, be carefui not to pinch
any interconnecting wires when repiacing this unit.

To replace the Acquisition unit, perform the previous steps in the reverse
order.

6-26

Maintenance

Corrective Maintenance

Battery Disposal and
First Aid

The instrument contains the following number of batteries on the following
boards:

■ two batteries (in the U500 and U51 1 RAM sockets) on the A5 Time
Base/Controller board

■ one battery (BT 1 30) on the A1 4 I/O board

■ one battery (BT 1 50) on the A1 8 Memory board

See Figures 6-10, 6-19, and 6-22 respectively, for the location of these
batteries.

WARNING

To avoid personal injury, observe proper procedures for the han-
dling of lithium batteries. Improper handling may cause fire,
explosion, or severe burns. Do not recharge, crush, disassemble,
heat the battery above 100° C (212° F), incinerate, or expose the
contents to water.

Battery Disposal

Dispose of the batteries according to local, state and federal regulations.

NOTE

Typically, small quantities (less than 20) can be safely disposed of
with ordinary garbage in a sanitary landfill.

Larger quantities must be sent by surface transport to a hazardous
waste disposal facility. The batteries should be individually pack-
aged to prevent shorting. Then, pack them into a sturdy container
that is clearly labeled, Lithium Batteries — DO NOT OPEN.

11801C Service Manual

6-27

Corrective Maintenance

Emergency and First Aid Information

In case of accidental contact with the lithium batteries, give your emergency

care provider the following information:

■ Manufacturer: Panasonic

■ Battery Type: Lithium Poly-Carbon monoflouride, BR 2/3 A

■ Solvent (electrolyte): Gama Butyriactone is of low toxicity. It can cause
some eye and respiratory irritation. According to the manufacturer, the
solvent may be released during venting. (Venting is an out gassing of
battery material.) This is usually caused by short circuiting (for more
than a few seconds) or by overheating.

■ Solute: LIBF4

Table 6-3 lists the emergency procedures to follow should you come in

contact with battery solvent.

Table 6-3:

Emergency Procedures for Contact with Battery Solvent

Contact

Do This:

Skin

Wash promptly with plenty of water.

Eyes

Flush immediately with plenty of water and use an emer-
gency eye wash, if available. Report to a medical profes-
sional for treatment.

Inhalation

Leave the area and get fresh air. Report to a medical
professional for treatment.

Ingestion

Non-toxic according to laboratory testing. However, re-
port to a medical professional for advice.

In case of venting, clear the immediate area. Venting will usually last only
a few seconds.

6-28

Maintenance

Corrective Maintenance

FRU Board and
Assembly Removal

Pin connectors are for electrical interconnection with chassis-mounted
components and other boards. Most boards/assemblies in the instrument
are mounted on the chassis. The following four boards plug onto the top of
the A13 Mother board (see Figure 6-7 for the location of these boards in the
card cage):

■ A1 4 Input/Output (I/O)

■ A1 5 Memory Management Unit (MMU)

■ A1 7 Executive Processor (EXP)

■ A1 8 Memory

The following two boards plug onto the A26 M/F Acquisition Interconnect
board (See Figure 6-1 for the locations of these boards in the Acquisition
unit):

■ A24/A27 Acquisition Analog

■ A25/A28 Acquisition MPU

Feed-through connectors join the plug-on boards to the A13 Mother board
and the A26 M/F Acquisition Interconnect board.

To minimize the chance of static charge damage to the integrated
circuits and/or related circuitry, after removing a board from the
instrument, place it on a grounded, antistatic surface.

Some components that are mounted on a board must be retained
for use with the new assembly. These components would include
interconnecting plugs, support posts, and some wiring.

11 801 C Service Manual

6-29

Corrective Maintenance

A15

Memory Management Plastic Board

Unit (MMU) Guides

/ \

i i

Rear Panel

A18

A14

A17

Memory

Input/Output

Executive Processor

WO)

(EXP)

Rear of Oscilloscope

Figure 6-7: Top View of the Card Cage

6-30

Maintenance

Corrective Maintenance

A1 M/F Strobe Drive Board

Removal and replacement steps are listed below. See Figures 6-8 and 6-32

for connector, screw, and index locations.

I I Step1: Place the instrument in the inverted position and remove the
bottom panel.

r~l Step 2: Remove connectors J1 6, J27, J28, J33A, J33B, J35, J36, J37,
J38, and J39 from the A1 M/F Strobe Drive board. Then remove connec-
tors J10, J18, and J34 from the A1 M/F Strobe Drive board. Note the
position of connectors from the A1 M/F Strobe Drive board index triangle
to ensure that the connectors can be correctly replaced.

NOTE

Record the positions of the connectors to ensure that the connec-
tors can be correctly replaced.

I I Step 3: Remove the five Torx head screws and carefully lift the board,
unplugging it from the J19 connector on the A1 M/F Strobe Drive board.

To replace the A1 M/F Strobe Drive board, perform the previous steps in

reverse order.

Torx Head

Figure 6-8: Removing/Replacing the A1 M/F Strobe Drive Board

11801C Service Manual

6-31

Corrective Maintenance

A3 M/F Power Connect Board

Removal and replacement steps are listed below. See Figures 6-2, 6-3, 6-9,
and 6-19 for connector, screw, and index locations.

I I Stepi: Remove the Power Supply module as described earlier in this
section.

NOTE

The chasis ground wire (green-yellow) wire may be removed from
the Power Supply module for this operation only.

Record the positions of all connectors to ensure that the connec-
tors can be correctly replaced.

I I Step 2: Remove the A1 M/F Strobe Drive board.

I I Step 3: Remove the A5 Time Base/Controller board.

I I Step 4: Remove the A4 Regulator board.

I I steps: Remove J90 from the A1 4 Input/Output board.

To replace the A3 M/F Power Connect board, perform the previous steps in
reverse order.

WARNING

To prevent electric shock or damage to the instrument, check that
the chassis ground wire is replaced on the Power Supply module.

6-32

Maintenance

11 801 C Service Manual

6-33

Corrective Maintenance

A4 Regulator Board

Removal and replacement steps are listed below. See Figures 6-2, 6-3, 6-9,
and 6-32 procedures for removal for connector, screw, and index locations.

r~l Step 1 : Remove the Power Supply module. (See the Power Supply
Module Removal procedure in this section.)

I I Step 2: Set the instrument upright position (if not already in this posi-
tion).

I I Step 3: Remove connectors J57 and J60 from the A4 Regulator board.
Note the position of the multi-pin connector’s index triangles to ensure
that the connectors can be correctly replaced.

I I Step 4: Remove the two Torx head screws from the metal heat sink
attached to the rear of this board.

NOTE

Now, the A4 Regulator board is not attached to the chassis. Howev-
er, it remains connected to the A3 M/F Power Connect board
through interconnecting pins.

r~l Step 5: Carefully unplug the J95 and J96 pins from the A4 Regulator
board by pulling the A4 Regulator board toward the rear.

I I Step 6: Remove the A4 Regulator board.

To replace the A4 Regulator board, perform the previous steps in reverse
order.

NOTE

Match the index triangle on the multi-pin connectors with the corre-
sponding square pad on the circuit board.

6-34

Maintenance

Corrective Maintenance

A5 Time Base/Controller Board
A6 Calibrator Board

Removal and replacement steps are listed below. See Figures 6-10 and 6-32

for connector, screw, and index locations.

I I Step 1 : Place the instrument in the inverted position.

I I Step 2: To remove the A6 Calibrator Board, remove connectors J1 and
J17 from the A6 Calibrator Board. Remove the Torx head screw securing
the board in place. Lift the board from J91 on the A5 Time Base/Control-
ler Board. Perform this process in reverse to replace the Calibrator
Board.

I I Step 3: To remove the A5 Time Base/Controller Board, remove connec-
tors J16, J29A, J30A, J32, J35, J91 , Ext Att, and Presc from the A5 Time
Base/Controller board. Use exteme care to prevent damage to the cable
center connector that was attached to Presc. Then, remove connectors
J18 and J83 from the A5 Time Base/Controller board. Note the position
of the multi-pin connector’s index triangles to ensure that the connectors
can be correctly replaced.

NOTE

Record the positions of the connectors and the receptacles to
ensure that these connectors and receptacles will be positioned
correctly when reinstalled.

I I Step 4: Remove the six Torx head screws holding the board in place.

I I Step 5: Remove the A5 Time Base/Controller board.

To replace the board, perform the previous steps in reverse order.

11801C Service Manual

6-35

Corrective Maintenance

J32

Ton Head
Screw (2)

J30A

J29A

J860

Ton Head
Screw (2)

Figure 6-10: Removing/Replacing the A5 Time Base/Controlier Board and A6 Calibrator Board

6-36

Maintenance

Corrective Maintenance

A7 CRT Socket Board and A8 CRT Driver Board

See Figures 6-1 , 6-4, 6-5, 6-7, 6-1 1,6-12, 6-1 3, 6-1 5, and 6-32 for board,
connector, screw, and index locations.

Remove and replace the A7 CRT Socket board and the A8 CRT Driver board
as follows:

I I Step 1 : Remove the three Torx head screws that secure the CRT cover,
and then remove the CRT cover.

I I Step 2: Remove the two plastic circuit board guides on top of the card
cage.

□ Step 3: Remove the two Torx head screws that secure the A7 CRT
Socket board cover, and then remove the A7 CRT Socket board cover.

□ Step 4: Slowly pull the A7 CRT Socket board toward the rear of the
instrument to unplug the A7 CRT Socket board from the CRT.

I I Step 5: Remove connectors J53 and J56 on the A7 CRT Socket board.
Note the positions of the multi-pin connector’s index triangles to ensure
that you can correctly replace these connectors.

^ARNIN^

The CRT anode voltage is 16 kV. To avoid electric shock, ground
the anode lead from the CRT to the chassis to short any stored
charge remaining in the CRT. Wait approximately ten minutes, then
ground the anode lead to the chassis again (refer to Step 6).

r~l Step 6: Use a non-conducting tool to pry up the anode lead cap. This
rubber cap is located on the upper part of the CRT, behind the front
casting. Using a non-conducting tool, release the spring clip inside the
cap and remove the anode. Insert one blade of a pair of needle-nose
pliers against the anode, and touch the other blade to the top of the
front casting to ground the anode to the chassis.

I I Step 7: Remove the single Torx head screw that secures the A8 CRT
Driver board to the instrument chassis. Use either of the following meth-
ods to remove the Torx head screw:

■ Remove the Torx head screw with a very short handled T-1 5 Torx
head screwdriver. Ensure that you do not strike the CRT while
removing the screw.

■ Remove the A1 0 Front Panel Control board. Then, use a Torx head
screwdriver that has an extension length inserted in it to remove the
Torx head screw. Access the screw from the hole in the left side of
the instrument chassis. Ensure that you do not strike the CRT while
removing the screw.

11801C Service Manual

6-37

Corrective Maintenance

I I Step 8: Remove the single Torx head screw that secures the transform-
er on the A8 CRT Driver board to the instrument chasis. This screw is
located at the rear of the transformer. The A8 CRT Driver board is now
not attached to the instrument chassis.

I I Step 9: Remove connectors J52, J56, and J57 from the A8 CRT Driver
board. Note the position of the multi-pin connector’s index triangles to
ensure that you can correctly replace these connectors.

I I Step 10: Lift the A8 CRT Driver board partially out of the instrument
chassis.

I I Step 1 1 : Remove connectors J54 and J55 from the A8 CRT Driver
board. Note the position of the multi-pin connector’s index triangles to
ensure that you can correctly replace these connectors.

I I Step 12: Remove the A8 CRT Driver board and the A7 CRT Socket
board.

I I Step 1 3: Unsolder the two wires that connect the A8 CRT Driver board
to the A7 CRT Socket board (the two boards are now separated).

To replace the A8 CRT Driver board and the A7 CRT Socket board, perform

the previous steps in reverse order.

Solder Points

J56

J53

Figure 6-1 1 : Removing/Replacing the A7 CRT Socket Board

6-38

Maintenance

Corrective Maintenance

11801C Service Manual

6-39

Corrective Maintenance

A9 Touch Panel Assembly

Removal and replacement steps are listed below. See Figures 6-5, 6-15, and
6-32 for connector, screw, and index locations.

Remove and replace the A9 Touch Panel assembly as follows:

□ Step 1 : Set the instrument on its right side. (The CRT will now be at the
top.)

□ Step 2: Use a 1/1 6-inch Allen wrench to loosen the small Allen screws
in each of the two control knobs.

I I Step 3: Slowly remove the two control knobs so that you do not lose
the small Allen screws inside the knobs.

I I Step 4: Remove the two Torx head screws at the bottom of the A9
Touch Panel Assembly.

I I Step 5: Lift up on the bottom of the A9 Touch Panel Assembly and
swing the assembly outward.

NOTE

The top of the A9 Front Panel Assembly Is held by two tabs. These
tabs fit Into two slots in the front-panel chassis.

I I Step 6: Remove the black ground wire from the quick-disconnect
ground connector on the front panel casting.

I I Step 7: Remove connector J73 from the A10 Front Panel Control board.
Note the position of multi-pin connector’s index triangles to ensure that
you can correctly replace this connector. Carefully remove the wire cable
through the slot provided in the front casting.

Cover the A9 Touch Panel Assembly with protective material once it is
removed since the plastic exterior may scratch.

To replace the A9 Touch Panel Assembly board, perform the previous steps
using the reverse process.

NOTE

Feed any slack cable from connector J73 to inside the chassis
(near the A10 Front Panel Control board). Be careful to not pinch
the interconnecting cable while replacing the front panel bezel.

6-40

Maintenance

Corrective Maintenance

A9 Touch Panel

Figure 6-13: A9 Touch Panel Assembly Torx Head Screws

1 '

— 1

J73

Connector

Figure 6-14: Removing/Replacing the A9 Touch Panel Assembly

11801C Service Manual

6-41

Corrective Maintenance

A10 Front Panel Control Board

Removal and replacement steps are listed below. See Figures 6-5, 6-1 1 ,

6-15, and 6-32 for connector, screw, and index locations.

I I Step 1 : Remove the CRT shield. (Refer to the Cathode Ray Tube Re-
moval procedure in this section, starting at Step 3.)

I I Step 2: Remove connectors J72, J73, J74, and J75 from the A1 0 Front
Panel Button board. Note the position of the multi-pin connector’s index
triangles to ensure that the connectors can be correctly replaced.

I I Step 3: Remove the two Torx head screws at the upper edge of the
board.

I I Step 4: Lift the board away from the guides at its bottom and remove it.

To replace the A10 Front Panel Control board, perform the previous steps in

reverse order.

6-42

Maintenance

Corrective Maintenance

A1 1 Front Panel Button Board

Removal and replacement steps are listed below. See Figures 6-5, 6-1 1 ,

6-15, 6-16, and 6-32 for connector, screw, and index locations.

I I Step 1 : Remove the CRT shield. (Refer to the removal instructions in the
Cathode Ray Tube Removal/Replacement procedure earlier in this
section, starting at Step 3.)

□ Step 2: Remove connector J75 from the A10 Front Panel Control board.
Note the position of connector index triangles for correct replacement.

I I Step 3: Remove the two Torx head screws from the A1 1 Front Panel
Button board, which is located at the top and near the inside center of
the front casting.

□ Step 4: Remove the All Front Panel Button board.

To replace the A1 1 Front Panel Button board, perform the previous steps in

reverse order.

Torx Head Screws (2)

Figure 6-16: Removing/Replacing the All Front Panel Button Board

6-44

Maintenance

Corrective Maintenance

A12 Rear Panel Assembly

Removal and replacement steps are listed below. See Figures 6-2, 6-17, and
6-32 for connector, screw, and index locations.

I I Step 1 : Remove the connectors from the RS-232-C, the GRIB, and the
PRINTER connector holders.

I I Step 2: Remove the eight Torx head screws from the outer edges of the
rear panel connector plate.

I I Step 3: Tilt the plate back from the instrument. Remove connector J78
from the top of the A1 2 Rear Panel assembly. Remove the grounding
wire. Note the position of the connector’s index triangles to ensure that
the connectors can be correctly replaced.

□ Step 4: Remove the rear panel connector plate and the attached A1 2
Rear Panel Assembly.

□ Step 5: Remove the following items from the rear panel plate:

■ two bail brackets, screws, and washers from the PRINTER connec-
tor

■ two posts from the GPIB connector

■ posts, lockwashers, and flat washers from the RS-232-C connec-
tor(s)

■ Torx head screw and washer (at lower left, if present)

□ Step 6: Remove the A1 2 Rear Panel Assembly from the rear panel
connector plate.

The metal covers on the PRINTER and on the GPIB connectors are
loose. If the board Is inverted, these covers will fall off.

To replace the A12 Rear Panel assembly, perform the previous steps in
reverse order.

NOTE

Replacement of connector J78 will be simplified if you replace the
connector before reinstalling the rear panel connector plate on the
rear of the chassis.

11801C Service Manual

6-45

Corrective Maintenance

A13 Mother Board

Removal and replacement steps are listed below. See Figures 6-7, 6-18, and
6-32 for connector, screw, and index locations.

I I Step 1 : Remove the three Torx head screws that secure the CRT cover,
and then remove the CRT cover. Remove the card cage retainer from
the top front of the card cage by removing the card cage’s two screws.
Remove both circuit board guides from the top of the card cage. The
other ends of the guides contain slots which attach to the edge of a
metal bracket. Both ends of the guides can be pried loose.

I I Step 2: Remove the A14 I/O, A15 MMU, A17 Executive Processor, and
A18 Memory boards. Note the position of the multi-pin connector’s index
triangles to ensure that the connectors can be correctly replaced.

NOTE

Tag the interconnecting plugs and mark the board locations to
ensure that the plugs can be correctly replaced as well.

I I Step 3: Remove connector J63A from the A1 3 Mother board.

□ Step 4: Remove the six Torx head screws.

I I Step 5: Remove the A13 Mother board.

To replace the A13 Mother board perform, perform the previous steps in
reverse order.

To prevent damage to the interconnecting wires, be careful not to
pinch the wires along the inside edge while replacing this board.

11801C Service Manual

6-47

Corrective Maintenance

Figure 6-18: Removing/Replacing the A13 Mother Board

6-48

Maintenance

Corrective Maintenance

A14 Input/Output (I/O) Board

See Figures 6-4, 6-7, 6-19, and 6-32 for board, connector, screw, and index

locations.

Remove and replace the A14 I/O board as follows:

I I Step 1 : Remove the three Torx head screws that secure the CRT cover,
and then remove the CRT cover.

□ Step 2: Remove both of the plastic board guides from the top of the
card cage. These guides are retained by two small catches located in
two holes in the left bracket of the card cage. The other ends of the
guides contain slots which attach to the edge of a metal bracket. Both
ends of the guides can be pried loose.

I I Step 3: Remove connectors J72, J77, J78, and J90 from the A1 4 I/C
board. Note the position of multi-pin connector’s index triangles to
ensure that you can be correctly replace these connectors.

I I Step 4: Lift the white, hinged tab at the upper, front edge of the board.
Pull the tab upward until the A14 I/C board separates from the A13
Mother board.

I I Step 5: Remove the A1 4 I/C board.

To replace the A14 I/C board, perform the previous steps in reverse order.

NOTE

Insert the board edges into the plastic guides at each end of the
card cage. Lower the board into position.

Ensure that connector P105 is seated on the A1 3 Mother board
connector. Push down firmly on the A1 4 I/O board to seat this
connector on the A1 3 Mother board.

WARNING

A lithium battery (BT130) is mounted on theA14 I/O board. Be
careful when placing the A1 4 I/O board on metal surfaces. If some
1C or battery leads are shorted, the battery may discharge or over-
heat and vent. (You can use plastic standoffs to prevent short
circuits.) This battery requires speciai handiing for disposal.
Refer to the instructions on Lithium Battery Disposal and First Aid
earlier in this section.

11 801 C Service Manual

6-49

Corrective Maintenance

J78

J77 J90

J72

Lithium Battery (to A1 3 Mother Board

(BT130) Connector)

Figure 6-19: Removing/Replacing the A14 I/O Board

6-50

Maintenance

Corrective Maintenance

A15 Memory Management Unit (MMU) Board

See Figures 6-4, 6-7, 6-20, and 6-32 for board, connector, screw, and index

locations.

Remove and replace the At 5 MMU board as follows:

I I Step 1 : Remove the three Torx head screws that secure the CRT cover,
and then remove the CRT cover.

□ Step 2: Remove both of the plastic board guides from the top of the
card cage. The guides are retained by two small catches located in two
holes in the left bracket of the card cage. The other ends of the guides
contain slots which attach to the edge of a metal bracket. Both ends of
the guides can be pried loose.

I I Step 3: Remove connectors J52, J53, J57, and J83 from the At 5 MMU
board. Note the position of the multi-pin connector’s index triangles to
ensure that you can correctly replace these connectors.

I I Step 4: Lift the white, hinged tabs at the front and rear edges of the At 5
MMU board. Pull the tabs upward until the At 5 MMU board separates
from the At 3 Mother board.

r~| Step 5: Remove the At 5 MMU board.

To replace the A15 MMU board, perform the previous steps in the reverse

order.

NOTE

Insert the board edges into the plastic guides at each end of the
card cage. Lower the board into position.

Ensure that connector P101 is seated onto the A1 3 Mother board
connector. Push down firmly on the A1 5 MMU board to seat this
connector on the A1 3 Mother board.

11 801 C Service Manual

6-5t

Corrective Maintenance

J83 J53 J57 J52

(To A13 Mother Board
Connector)

Figure 6-20: Removing/Replacing the A15 MMU Board

6-52

Maintenance

Corrective Maintenance

A1 7 Executive Processor (EXP) Board

See Figures 6-4, 6-7, 6-21 , and 6-32 for board, connector, screw, and index

locations.

Remove and replace the A17 Executive Processor board as follows:

I I Step 1 : Remove the three Torx head screws that secure the CRT cover,
and then remove the CRT cover.

I I Step 3: Remove connector J77 from the A1 7 Executive Processor
board. Note the position of the multi-pin connector’s index triangle to
ensure that you can correctly replace this connector.

I I Step 4: Lift the white, hinged tabs at the front and rear edges of the
board. Pull the tabs upward until the A17 Executive Processor board
separates from the A13 Mother board.

I I Step 5: Remove the A1 7 Executive Processor board.

To replace the A17 Executive Processor board, perform the previous steps in

reverse order.

NOTE

Insert the board edges into the plastic guides at each end of the
card cage. Lower the board into position.

Ensure that connector P104 on the A17 Executive Processor board
is seated onto the of A1 3 Mother board connector. Push down
firmly on the A1 7 Executive Processor board to seat this connector
on the A1 3 Mother board.

11 801 C Service Manual

6-53

Corrective Maintenance

A18 Memory Board

See Figures 6-4, 6-7, 6-21 , 6-22, and 6-32 for board, connector, screw, and

index locations.

Remove and replace the A18 Memory board as follows:

I I Step 1 : Remove the three Torx head screws that secure the CRT cover,
and then remove the CRT cover.

I I Step 3: Remove connector J77 from the A1 7 Executive Processor
board. Note the position of the multi-pin connector’s index triangle to
ensure that you can correctly replace this connectors.

I I Step 4: Lift the white, hinged tabs at the front and rear edges of the
board. Pull the tabs upward until the A18 Memory board separates from
the A13 Mother board.

I I Step 5: Remove the A1 8 Memory board.

To replace the A18 Memory board, perform the previous steps in reverse

order.

NOTE

Insert the edges of the board into the plastic guides at each end of
the card cage. Lower the board into position.

Ensure that connector P106 is seated onto the A1 3 Mother board
connector. Push down firmly on the A1 8 Memory board to seat this
connector on the A1 3 Mother board.

WARNING

A lithium battery (BT130) is mounted on the A1 8 Memory board. Be
careful when placing the A1 8 Memory board on metal surfaces. If
some 1C or battery leads are shorted, the battery may discharge or
overheat and vent. (You can use plastic standoffs to prevent short
circuits.) This battery requires speciai handiing for disposal.
Refer to the instructions on Lithium Battery Disposal and First Aid
earlier in this section.

11801C Service Manual

6-55

Corrective Maintenance

A19 Strobe/TDR Buffer Board

Removal and replacement steps are listed below. See Figures 6-23, 6-26,
and 6-32 for connector, screw, and index locations.

I I Step 1 : Remove the Acquisition unit and position the Acquisition unit in
the upright position.

I I Step 2: Remove the two Torx head screws on each black retaining
brace located at the top of the Acquisition unit to remove these braces.

r~| Step 3: Remove connectors J1 A, J2A, J3A, J4A, JIB, J2B, J3B, J4B,

J1 C, J2C, J3C, J4C, J29A, J30A, J32, J33A, J33B, and J34 from the A1 9
Strobe/TDR Buffer board.

NOTE

Record the positions of the connectors and the receptacles to
ensure that the connectors can be correctly replaced.

I I Step 4: Remove J1 0 from the A26 M/F Acquisition Interconnect board.

□ Step 5: Remove the two Torx head screws on the bottom of the A1 9
Strobe/TDR Buffer board, and gently pull out the board.

To replace the At 9 Strobe/TDR board, perform the previous steps in reverse
order.

11801C Service Manual

6-57

Corrective Maintenance

J2A J1A J32 J4A J3A J1C J2C J3C J4C J33A J33B

Figure 6-23; Removing/Replacing the A19 Strobe/TDR Buffer Board

6-58

Maintenance

Corrective Maintenance

A20-A23 Head Interconnect Boards

Removal and replacement steps are listed below. See Figures 6-23, 6-24,

6-25, 6-26, 6-28, 6-29, and 6-32 for connector and screw locations.

I I Step 1 : Remove the Acquisition unit and place the Acquisition unit in
the upright position.

I I Step 2: Remove the two Torx head screws on each black retaining
brace located at the top of the Acquisition unit.

I I Step 3: Remove the A24/A27 Acquisition Analog boards, the A25/A28
Acquisition MPU boards, and the A19 Strobe/TDR Buffer board.

I I Step 4: Remove the four screws holding the top of the front subpanel of
the Acquisition unit.

I I Step 5: Remove the four screws on the gold-colored locking bar lo-
cated on the top front of the Acquisition unit.

I I Step 6: Turn the Acquisition unit in the inverted position and repeat
Steps 4 and 5 on the bottom of the Acquisition unit.

I I Step 7: Remove the connectors from the A26 M/F Acquisition Intercon-
nect board connector. Note the position of the multi-pin connector’s
index triangle to ensure that the connector can be correctly replaced.

I I Step 8: Remove the Front Subpanel assembly with the A20-A23 Head
Interconnect boards intact.

I I Step 9: Remove the bottom Torx head screw from within the sampling
head compartment that contains the head interconnect board you are
removing.

I I Step 10; Turn the Front Subpanel assembly around so that the open
compartments face away from you.

I I Step 11: Remove the top nut that fastens the sampling head compart-
ment to the head interconnect board you are removing.

J1I2I3I4

Figure 6-24: Removing/Replacing the A20-A23 Head Interconnect Boards

11801C Service Manual

6-59

Corrective Maintenance

Front View of Front Subpanel Assembly

Sampling Head
Compartments

Torx Head Screws

Torn Head Screws

Rear View of Front Subpanel Assembly

A20-A23 Head
Interconnect
Boards

A20- A23 Head Interconnect A20- A23 Head Interconnect

Board Retaining Nuts Board Retaining Nuts (Power Only)

Figure 6-25: Removing/Replacing the Front Subpanel Assembly

I I Step 12: Remove the head interconnect board by slightly prying up on
the tabs that are keeping it in place, and slowly remove the board(s)
from the J1/2/3/4 connector.

To replace the A20-A23 Head Interconnect boards, perform the previous
steps in reverse order.

6-60

Maintenance

Corrective Maintenance

A26 M/F Acquisition Interconnect Board

Removal and replacement steps are listed below. See Figures 6-23, 6-25,

6-26, 6-27, 6-28, 6-29, and 6-32 for connector, screw, and index locations.

I I Step 1 : Remove the Acquisition unit as and place the Acquisition unit in
the upright position.

I I Step 2: Remove the A24/A27 Acquisition Analog board, the A25/A28
Acquisition MPU board and the A19 Strobe/TDR Buffer board.

I I Step 3: Remove the four screws on the gold colored retaining brace
holding the top of the Front Subpanel assembly of the Acquisition unit.

I I Step 4: Remove the four screws on the gold colored locking bar located
on the top front of the Acquisition unit.

I I Step 5: Turn the Acquisition unit in the inverted position and repeat
Steps 3 and 4 on the bottom of the Acquisition unit.

r~| Step 6: Remove connectors J1 1 , J1 2, J1 3, and J1 4 on the A26 M/F
Acquisition Interconnect board. Note the position of the multi-pin con-
nector’s index triangle to ensure that the connector can be correctly
replaced.

Figure 6-26: Removing/Replacing the A26 M/F Acquisition interconnect Board

11801C Service Manual

6-61

Corrective Maintenance

I I Step 7: Remove the Front Subpanel assembly with the head intercon-
nect boards intact.

I I Step 8: Remove the six Torx head screws to remove the A26 M/F Ac-
quisition Interconnect board.

To replace the A26 M/F Acquisition Interconnect board, perform the previous
steps in reverse order.

Acquisition
Unit Chassis

A26 M/F
Acquisition
Interconnect
Board

Torx Head Screws (6)

Figure 6-27: Top View of the A26 Mainframe Acquisition interconnect Board

6-62

Maintenance

Corrective Maintenance

A24/A27 Acquisition Anaiog Boards

Removal and replacement steps are listed below. See Figures 6-23, 6-26,

6-28, and 6-32 for board guide, screw, and index locations.

I I Step 1 : Remove the Acquisition unit and place the Acquisition unit in
the upright position.

I I Step 2: Remove the two Torx head screws on each black retaining
brace located at the top of the Acquisition unit; remove these braces.

I I Step 3: Remove connectors J41 , J42, J43, and J44 from the A24/A27
Acquisition Analog board.

I I Step 4: Pull up on the hinged white tabs until the board separates from
connector P6.

To replace the A24/A27 Acquisition Analog board, perform the previous

steps in reverse order.

NOTE

Insert the edges of the board into the plastic guides. Lower the
board into position.

Check that connector is seated onto the A26 M/F Acquisition Inter-
connect board connector. Push down firmly on the A24IA27 Ac-
quisition Analog board to seat this connector on the A26 MjF
Acquisition Interconnect board.

J41 J42 J43 J44

Figure 6-28: Removing/Replacing the A24/A27 Acquisition Analog Boards

11801C Service Manual

6-63

Corrective Maintenance

A25/A28 Acquisition MPU Boards

Removal and replacement steps are listed below. See Figures 6-23, 6-26,
6-29, and 6-32 for board guide, screw, and index locations.

I I Step 1 : Remove the Acquisition unit and place it in the upright position.

I I Step 2: Remove the two Torx head screws on each black retaining
brace located at the top of the Acquisition unit; remove these braces.

I I Step 3: Pull up on the hinged white tabs until the board separates from
connector P8 on the A26 M/F Acquisition Interconnect board.

To replace the A25/A28 Acquisition MPU board, perform the previous steps
in reverse order.

NOTE

Insert the edges of the board into the plastic guides. Lower the
board into position.

Check that the connector is seated onto the A26 M/F Acquisition
Interconnect board connector. Push down firmly on the A25/A28
Acquisition MPU board to seat this connector on the A26 M/F
Acquisition Interconnect board.

✓

P7/8 (to A26 M/F Acquisition
interconnect Board Connector)

Figure 6-29: Removing/Replacing the A25/A28 Acquisition MPU Boards

6-64

Maintenance

Corrective Maintenance

FRU 1C Removal

The procedures for removing and replacing the FRU ICs in the oscilloscope
are outlined in this section.

Serial Data Interface Integrated Circuits (“Slam-Pack” ICs)

U330 is mounted on the At 4 I/O board. See Figure 6-30 for the location of
this 1C. It has a raised, ridged, heat sink cover. The 1C is oriented to its
socket by a beveled corner. The other corners are notched to fit the edges
of the socket. The beveled corner aligns with a spring (small metal tab) at
one corner of the socket. An example of the 1C is shown in Figure 6-32.

To remove the Serial Data Interface 1C, proceed as follows:

I I Step 1 : Remove the At 4 I/C board.

I I Step 2: Hold the heat sink cover in place and unfasten the retaining clip
by moving the retaining clip across the tabs while pushing down slightly
on the cover.

I CAUTION I

To prevent static damage to the instrument or components, observe
ali the special precautions mentioned under Static-Sensitive Classi-
fication in this section.

I I Step 3: Remove the cover slowly to prevent the IC from falling out. Note
the position of the index of the IC for later use before removing the IC.

I I Step 4: Remove the IC with tweezers.

Finger oils can degrade reliability of components. Avoid touching
the IC or its socket contacts with your fingers.

11801C Service Manual

6-65

Corrective Maintenance

Replace the Serial Data Interface 1C as follows:

I I Step 1 : Using tweezers, place the beveled corner of the replacement IC
against the index spring (the original positioning of this index was noted
earlier).

Do not damage the spring by improperly seating the beveled
corner because shorting of the two corner contacts could result.

□ Step 2: Arrange the other corners with the tweezers to fit evenly at the
edges of the socket.

□ Step 3: Set the cover flat on the IC with the cover’s end tabs properly
aligned with, but not in, the mating recesses in the socket.

□ Step 4: Push down on the cover, keeping it flat on the IC. Slide the
cover end tabs into place. Hold it there while moving the retaining clip
over the tabs at the other end of the cover.

□ Step 5: Slightly pull on the cover to check that the cover is secure.

r~l Step 6: Replace the A14 I/O board.

6-66

Maintenance

Time Base Processor Firmware

U310 U300 U400 U410

A5-Time Base/Controller

Dispiay Processor
Firmware

U140 U150

A1 5-Memory Management Unit

Figure 6-:

11 801 C Service Manual

Corrective Maintenance

Seriai Data
interiace iC

U330

A1 4 -Input/Output (I/O)

A1 8-Memory

Acquisition Processor
Firmware

U611

tion MPU

6-67

Corrective Maintenance

Firmware Integrated Circuits (“Dual In-Line Package” ICs)

The firmware ICs are located on five separate boards (see Figure 6-30 for
the 1C locations on each circuit board). The boards and their respective
firmware (FW) are:

■ A5 Time Base/Controller board — Time Base Processor FW (U300,
U310, U400 and U410)

■ A15 MMU board — Display Processor FW (U140 and U150)

■ A18 Memory board — Main Processor FW (U800, U810, U820, U830,
U900, U910, U920 and U930)

■ A25 and A28 Acquisition MPU boards — Acquisition Processor FW
(U611)

All of the ICs listed above are ordered by a single Tektronix part number, as
a single firmware kit. (Each iC cannot be ordered separately.) For the
1 1 801 C, the firmware kit number is 020-1 889-XX.

To remove and replace the firmware ICs in your oscilloscope, follow these
procedures:

WARNING

Dangerous shock hazards may be exposed when the instrument
covers are removed. Before proceeding, ensure that the oscilio-
scope PRINCIPAL POWER SWITCH is in the OFF position. Then,
disconnect the instrument from the power source. Disassembiy
should only be attempted by qualified service personnel.

To prevent static damage to the instrument, observe alt the special
precautions mentioned under Static-Sensitive Ciassification in this
section.

6-68

Maintenance

Corrective Maintenance

Firmware Upgrade Procedure

To upgrade or replace your firmware ICs, complete the following steps:

I I Step 1 : Prepare the instrument for the firmware upgrade procedure as

follows:

■ Set the PRINCIPAL POWER SWITCH to OFF, and remove the power
cord.

■ Place the instrument on its right side (if not already in this position)
to provide access to the boards upgraded in the firmware upgrade
procedure that follows.

I I Step 2: Access boards within the card cage as follows:

■ Ensure that the PRINCIPAL POWER SWITCH is set to OFF and the
power cord is unplugged.

■ Remove the instrument’s top panel cover.

■ Remove the two plastic board guides from the top of the card cage
(at the left rear of the instrument).

■ Remove the three Torx head screws that secure the CRT cover, and
then remove the CRT cover (see Figure 6-4).

Figure 6-31: IC Insertion-Extraction Tool

11801C Service Manual

6-69

Corrective Maintenance

I I Step 3: Upgrade the A1 5 MMU board firmware as follows:

■ Remove the A1 5 MMU board from the card cage. The A1 5 MMU
board is typically located farthest from the outside (left side) of the
instrument.

■ Locate the two firmware ICs, U140 and U150.

To prevent damage to the firmware ICs or the board, ensure pin 1 is
positioned correctly when replacing components.

NOTE

Use the 1C Insertion-Extraction Pliers shown in Figure 6-31 for
removing and replacing the ICs. (Refer to Table 4-2, Test Equip-
ment for the part number of these pliers.)

Do not use the label on the 1C for an index because it may be
applied incorrectly. See Figure 6-32 for the correct location of the
index on the 1C.

■ Remove U140 and replace it with the upgraded IC. The last two-digit
portion of the part number on the replacement IC should be the
same as, or higher than, that on the removed IC. Ensure that pin 1 is
oriented correctly.

■ Similarly replace U1 50 with the upgraded IC.

I I Step 4: Upgrade the A1 8 Memory board firmware as follows:

■ Remove the A1 8 Memory board from the card cage. The A1 8
Memory board is typically located one slot from the outside (left
side) of the instrument.

■ On the A1 8 Memory board, replace the following ICs:

U800

U900

U812

U910

U820

U920

U830

U930

In each case, the last two-digits of the part number on the replace-
ment IC should be the same as, or higher than, that on the removed
IC. Again, ensure that pin 1 is oriented correctly.

■ Return the A1 8 Memory board to its former location in the card
cage.

6-70

Maintenance

Corrective Maintenance

I I Step 5: Upgrade the A5 Time Base/Controller board firmware as fol-
lows:

■ Locate U300, U31 0, U400, and U41 0 on the A5 Time Base/Controller
board (see Figure 6-30). These components are found near the
bottom front of the instrument with the instrument positioned on its
right side.

■ Replace U300, U310, U400, and U410 on the A5 Time Base/Control-
ler board.

The last two-digit portion of the part number on the replacement IC
should be the same as, or higher than, that on the removed IC.
Again, ensure that pin 1 is oriented correctly.

I I Step 6: Upgrade the A25/A28 Acquisition MPU board firmware as
follows:

■ Remove the Acquisition unit from the instrument.

■ Remove the A25/A28 Acquisition MPU board from the Acquisition
unit (see Figure 6-1 for the exact location of these boards in the
Acquisition unit).

■ Locate U61 1 on the A25/A28 Acquisition MPU board (see Fig-
ure 6-28). This board is located in the card cage.

■ Replace U61 1 on the A25/A28 Acquisition MPU board.

The last two-digit portion of the part number on the replacement IC
should be the same as, or higher than, that on the removed IC.
Ensure that pin 1 is oriented correctly.

11 801 C Service Manual

6-71

Corrective Maintenance

I I Step 7: Verify the instrument serial number as follows:

■ Locate the manufacturing jumper, J860, on the A5 Time Base/Con-
troller board (see Figure 6-10), and install the terminal connector
link.

■ Connect a power cord to the instrument.

■ Connect a terminal or controller to the oscilloscope. Refer to the
11801C User Manual for more information on this connection.

■ Set the PRINCIPAL POWER SWITCH and ON/STANDBY switch to
ON.

■ Set necessary communication parameters; for example, baud rate.

■ After the instrument is powered-on, to establish communication from
the terminal or controller, enter the following commands (<CR> is
the return key):

e<CR>

v<CR>

■ Verify that the serial number on the instrument’s front panel matches
the mainframe ID number in the Identify pop-up menu in the UTIL-
ITY major menu.

■ If the numbers do not match, then enter the command:
uid main:”BXXXXXX”<CR>

where XXXX corresponds to the serial number digits found on the
front panel serial number marker.

■ Verify that the proper ID is now displayed in the Identify pop-up
menu, in the Utility major menu.

r~| Step 8: Remove the procedure setup as follows:

■ Set the PRINCIPAL POWER SWITCH to OFF.

■ Remove the J860 manufacturing jumper from the A5 Time Base/
Controller board.

■ Replace the bottom instrument cover, and set the instrument up-
right.

6-72

Maintenance

Corrective Maintenance

I I Step 9: Perform the final power-on and verification as follows:

NOTE

You must now perform the power-on sequence again for the instru-
ment to recognize the new manufacturing jumper configuration.

■ Set the PRINCIPAL POWER SWITCH and ON/STANDBY switch to
ON.

■ Verify that the instrument powers-on and successfully completes the
Self-Test diagnostics.

NOTE

If probiems are encountered, then check for the following:

■ all components are properly oriented in the sockets

■ all component pins are properly seated

■ components are installed in the correct location

11801C Service Manual

6-73

Corrective Maintenance

Slam-Pack 1C

Note: Match the index triangle on the multi-pin connectors with the
corresponding square pad on the circuit board.

Figure 6-32: Multi-Pin Connector Orientation and Semiconductor Indexing Diagram

6-74

Maintenance

Corrective Maintenance

Cables and
Connectors

Cabling diagrams are provided in the Diagrams section to show the inter-
connecting cables between the various circuit boards, modules, and assem-
blies. Use these diagrams as a reference when you are removing and/or
replacing cables between these units.

Interconnecting Pins

Two types of connectors are used for these interconnecting pins. If the
connector is mounted on a plug-on board, a special socket is soldered into
the board. If the connector is on the end of a lead, an end-lead pin connec-
tor is used which mates with the interconnecting pin. The following informa-
tion provides the removal and replacement procedure for the various types
of interconnecting methods.

Coaxial-type End-Lead Connectors (Peltolas & SMB)

These connectors use color coding of wires, which may be helpful to corre-
late a Peltola connector to its socket on a circuit board. The wire insulation’s
color, or its colored stripe, is the same as the color represented by the last
digit of the JXX component number. (EXAMPLE: a green wire would connect
to a JOS socket.) Other Peltola connectors may have labels which designate
their JXX component number.

Multi-Pin Connectors

These connectors are arranged so that the pin connectors used to connect
the wires to the interconnecting pins are clamped to the ends of the
associated leads.

Some of the pin connectors are grouped together and mounted in a plastic
holder. The overall result is that these connectors are installed and removed
as a multi-pin connector.

Pin 1 on multi-pin connectors is designated with a triangle (or arrowhead). A
triangle, dot, or square printed on circuit boards denotes pin 1 . When a
connection is made to a circuit board, the position or orientation of the

Two methods of interconnection are used to electrically connect circuit
boards with other boards and components. When the interconnection is
made with a coaxial cable, a special end-lead connector plugs into a socket
on the board. Other interconnections are made with a pin soldered into the
board.

11801C Service Manual

6-75

Corrective Maintenance

triangle on the multi-pin holder is determined by the index (triangle, dot or
square) printed on the circuit board. Most board-mounted connectors have
a square pad for pin 1 . (See Figure 6-32.)

NOTE

Match the index triangle on the multi-pin connectors with the corre-
sponding square pad on the circuit board.

Some multi-pin connectors are keyed by a gap between the pin 1
and 3 positions in the holder. (A small plastic plug covers the pin 2
position on the end of the holder.) There Is a corresponding gap
between pins 1 and 3 on the circuit board.

Align the plug in the multi-pin holder with the gap between the
circuit board pins. The connector is then ready to be installed.

Many of the larger, multi-pin ribbon connectors have a red, blue, or other
contrasting color line along one side of their attached wire cables. This line
indicates the location of pins 1 and 2 and also the location of the corre-
sponding triangle index mark on the connector.

Some of the gray-colored ribbon cables may have the number of their
connectors stamped on them.

The ribbon connectors have the following two functions:

■ to provide a strain relief for the wire connections. The wire ribbon is
wrapped around a bar between the wire connections and the top of the
connector. Strain is then felt between the wires and the top of the con-
nector. This relieves most of the strain which would otherwise be felt on
the wire connections.

■ to provide a pull-tab to ease disconnection. The pull-tab is attached
inside the connector. When the tab is pulled, even pressure is applied
across the connector. The connector then separates easily from its
holder.

NOTE

To remove these ribbon connectors, grasp the pull-tab (fastened
Into the connector, if there) and pull it loose from the holder.

If there isn’t a pull-tab present in the connector, grasp the ends of
the connector instead. Pull It straight out from the connector sock-
et.

6-76

Maintenance

Corrective Maintenance

Checks After FRU
Replacement

After any FRU has been replaced, that particular unit should be checked.
Table 6-4 lists the required checks (and the respective procedure name) to
perform.

Table 6-4: Checks Required After FRU Replacement

FRU Replacement

Checks Required

A1 Strobe Drive Board

Power-On Diagnostics
Extended Diagnostics
Internal Clock

A3 M/F Power Connect
Board

Power-On Diagnostics
Extended Diagnostics

A4 Regulator Board

Power-On Diagnostics
Extended Diagnostics
Power Supply
Vertical Reference Voltage
Vertical Accuracy
System Vertical RMS Noise
Sweep Rate Accuracy
Triggering

A5 Time Base/Controller
Board

Power-On Diagnostics
Extended Diagnostics

A8 CRT Driver Board

Display

A9 Touch Panel Assembly

Power-On Diagnostics
Extended Diagnostics

A10 Front Panel Control
Board

Power-On Diagnostics
Extended Diagnostics

A1 1 Front Panel Button
Board

Power-On Diagnostics
Extended Diagnostics

A1 2 Rear Panel Board

Power-On Diagnostics
Extended Diagnostics

A13 Mother Board

Power-On Diagnostics
Extended Diagnostics

A14 Input/Output Board

Power-On Diagnostics
Extended Diagnostics
Real Time Clock

A15 MMU Board

Power-On Diagnostics
Extended Diagnostics

A1 7 Executive Processor
Board

Power-On Diagnostics
Extended Diagnostics

A18 Memory Board

Power-On Diagnostics
Extended Diagnostics

11801C Service Manual

6-77

Corrective Maintenance

Table 6-4: Checks Required After FRU Replacement (Cent.)

FRU Replacement

Checks Required

A1 9 Strobe/TDR Buffer
Board

Power-On Diagnostics
Extended Diagnostics
Sweep Rate Accuracy
Internal Clock

A20-A23 Head Interconnect
Boards

Power-On Diagnostics
Vertical Accuracy
System Vertical RMS Noise

A26 M/F Acquisition
Interconnect Board

Power-On Diagnostics
Extended Diagnostics
Vertical Reference Voltage

A24/A27 Acquisition Analog
Boards

Power-On Diagnostics
Extended Diagnostics
Vertical Accuracy
System Vertical RMS Noise

A25/A28 Acquisition MPU
Boards

Power-On Diagnostics
Extended Diagnostics

Firmware ICs

Power-On Diagnostics
Extended Diagnostics

Cathode Ray Tube (CRT)

Display

Power Supply Module

Power-On Diagnostics
Extended Diagnostics
Power Supply
Vertical Reference Voltage
Vertical Accuracy
System Vertical RMS Noise
Sweep Rate Accuracy

6-78

Maintenance

Diagnostic Troubieshooting

This section provides the information necessary to troubleshoot a faulty
oscilloscope to the field replaceable unit (FRU) level. In most cases, an FRU
is a circuit board. The primary means for troubleshooting is to use the error
index code output from the Kernel diagnostics and cross-reference them to
the suspect circuit boards in the following tables, or to use the built-in FRU
help function available in Extended Diagnostics. In addition, conventional
troubleshooting techniques are described at the end of this section to help
identify a faulty A4 Regulator board, CRT, Power Supply module, A13 Mother
board, or A8 CRT Driver board.

Diagnostics Ovorviow subsystem processors (Executive, Display, Time Base, and Acquisition)

execute a set of Kernel diagnostics prior to the Self-Test diagnostics. After
the Acquisition processor has verified its support circuitry, it tries to establish
communication with the Time Base processor. After the Time Base proces-
sor has verified its critical support circuitry and after it has attempted to
communicate with the Acquisition processor, the Time Base processor
attempts to communicate with the Executive processor. Likewise, the Dis-
play processor attempts to communicate with the Executive processor after
successfully executing its Kernel diagnostics.

After a processor has successfully completed its Kernel diagnostics and
established communications with the next order processor (for example,
Acquisition-to-Time Base and Time Base-to-Executive), then the Self-Test
diagnostics execute to verify the more global functionality of the processor’s
hardware system. After all the Self-Test diagnostics are executed, any fail-
ures cause the oscilloscope to enter Extended Diagnostics and to display
the error index codes in a diagnostic menu. Extended diagnostics contains
tests which are a superset of the Self-Test.

The Kernel diagnostics (low-level Self-Test diagnostics) and Self-Test/Ex-
tended Diagnostics produce and format error index codes differently, so
they are covered separately. Kernel diagnostics error index codes for each
subsystem are produced and read quite differently from each other.

Note that some of these tests that may indicate faulty FRU(s) are not
executed automatically during the Self-Test diagnostics (that is, some errors
codes are only generated by manually selecting tests or Extended Diagnos-
tics).

11801C Service Manual

6-79

Diagnostic Troubieshooting

Kernel Diagnostics

Kernel diagnostics are executed each time the front panel ON/STANDBY
switch is set to ON. The oscilloscope performs power-on diagnostics on its
microprocessor subsystems and Self-Test diagnostics on all of its major
circuits.

When Kernel diagnostics begin, the messages Diagnostics in Progress
and Comm Test in Progress are displayed. If the oscilloscope is being
powered-on from a cold condition, then the diagnostics may complete
before the CRT is warmed up and able to display these messages.

Diagnostic routines are performed in parallel on each of the instrument’s
processor subsystems: Display, Executive, Time Base, and Acquisition.
Following successful execution of their Kernel diagnostics, the Acquisition
processor attempts to communicate with the Time Base processor and the
Time Base and Display processors attempt to communicate with the Execu-
tive processor.

The Executive processor will continue Self-Test diagnostics even if it is the
only processor that has successfully completed its Kernel diagnostics.

In the case where the Display processor has not communicated successfully
with the Executive processor, the message indicating that Self-Test diagnos-
tics are beginning will not appear on the screen. Kernel diagnostic failures
may be indicated by the message, Dsy Kernel Failure, or Comm Test in
Progress on the screen and/or a single high-low beep and illuminated
menu buttons.

If either the Display, Time Base, or Acquisition processors do not successful-
ly pass their communications stage, then the oscilloscope automatically
enters Extended Diagnostics at the end of the Self-Test diagnostics. If the
Display processor is at fault, then the Extended Diagnostic menu will not
appear on the screen.

The Kernel diagnostic tests execute concurrently in all three subsystem
processor circuits at power-on. Hardware critical to diagnostic operation is
verified, such as ROM, RAM, DMAs, timers, and interrupt control circuitry.

For the Executive Processor, this requires checking basic operation for most
boards in the card cage (that is, those boards plugged in to the At 3 Mother
board). The last step of Kernel diagnostics for the Display, Time Base, and
Acquisition processors is to verify communication. Within each processor, all
Kernel diagnostics must execute without failures before the Self-Test diag-
nostics can execute. However, the Executive processor continues with its
Self-Test diagnostics despite a communication failure encountered with the
Display and/or Time Base processors; and the Time Base processor does
not halt when it has a communication failure with the Acquisition processor.

Since the condition of the instrument is unknown at power-on, when a kernel
failure occurs. Kernel diagnostics in the Executive, Time Base, and Acquisi-
tion processors do not attempt to display error index codes. Instead, these
processors generate hexidecimal (hex) numbers that are read as a series of
binary bits, such as XXX1 01 01 (hex error code 1 5/,ex) for the Executive
processor: 01 00 (hex error code %ex) for the Time Base processor; or

6-80

Maintenance

Diagnostic Troubleshooting

1 0 (hex error code for the Acquisition processor, from either internal
test points or LEDs. Refer to Tables 6-10, 6-15, and 6-16 for more informa-
tion and examples of these hex error codes.

The Display kernel diagnostics display an error message on the screen
giving the name of the test that failed. For example, the following message
indicates that the DMA 0 test failed:

Dsy Kernel Failure
DMAO

If the error message does not appear on the screen, the error index code
can be obtained from the status LEDs and pins on the A15 Memory Man-
agement Unit board (see Figure 6-34).

Self-Test/Extended

Diagnostics

Refer to the Power-On Diagnostics procedure in the Performance Verification
section for information about Self-Test/Extended Diagnostics.

Extended Diagnostics Menu Structure

The menu structure determines the format of the error index codes. The
Extended Diagnostics menus are a four-level hierarchy with the Subsys (that
is, the Subsystem) menu at the highest level. This four-level Subsystem,
Block, Area and Routine menu hierarchy generates the error index codes.
Each subsystem in the Subsystem menu can be selected and tested if there
are functional processor(s) and communication paths. Each subsystem is
broken into a number of parts, or circuit blocks, in the Block menu for the
selected subsystem. In a similar manner, each block is broken into a num-
ber of circuit areas in the Area menu, the third level. The fourth and lowest
menu level is the Routine menu, which contains the smallest test unit that
can be selected and executed.

Extended Diagnostics Error Index Codes

The error index codes for the Extended Diagnostics are five-digit codes
whose first character indicates the subsystem tested. The last four digits are
hexadecimal (^ex) numbers that indicate the Block, Area, Routine, and
specific failure mode. For example, E2321 is decoded as follows:

E Subsystem — Executive

2 Block name — Front Panel

3 Area name — Soft Keys

2 Routine name — Column Open
1 Failure Identity — specific failure mode

Table 6-5 lists the subsystem character for the Extended Diagnostic error
index codes.

11 801 C Service Manual

6-81

Diagnostic Troubieshooting

Table 6-5: Extended Diagnostics Error index Code Descriptions

Description

Meaning

Executive

Display

Time Base

Mainframe Acquisitions

SM-11 multi-channel unit A Acquisition

SM-11 multi-channel unit B Acquisition

SM-1 1 multi-channel unit C Acquisition

SM-1 1 multi-channel unit D Acquisition

Front panel controls are active during the Seif-Test diagnostics sequence
and any disturbance may cause a test faiiure, forcing the oscilloscope into
the Extended Diagnostics mode. Touch the (E)Exit label twice in succession
to remove the Extended Diagnostics menu and resume normal operation. In
situations where the Dispiay, Time Base, or Acquisition processors have
failed their kernel diagnostics, exiting diagnostics to normai operation will
not be possible.

After the Self-Test/Extended Diagnostic programs have executed, any resul-
tant error index codes appear on the display next to the associated subsys-
tem name in the Extended Diagnostics menu. Each subsystem that had a
failure gives the first error encountered and the number of faiiures in the
subsystem.

To get a more complete list of the error index codes in a subsystem, touch
the selector of a failed subsystem (if the failed subsystem is not already
selected) and then touch the Block selector. Touching the Area and then
Routine selectors shows the lowest level test routines in the selected Block.
The currently selected Subsystem, Block, Area, and Routine are shown
below their labels at the bottom of the Extended Diagnostics menu. Several
function and operating mode selectors are also available at the bottom of
the screen. When certain test routines are selected, some of these operating
modes are non-selectable. Additionally, when some of the operating modes
are set to certain states, some of the test routines may become non-select-
able.

The function and mode operators are listed below:

■ (?)Help — displays a list of FRUs for the currently selected routine. If the
routine had a failure, then the error index code for that routine is also
displayed. The FRUs are normally listed as the most-to-least probable
cause for errors in the routine. In some cases, the FRUs are listed ac-
cording to their ease-of-replaceability in order to minimize the time
required to identify the faulty FRU.

6-82

Maintenance

Diagnostic Troubleshooting

Within this menu, you can scan forward to the next routine or the next
failure by touching the appropriate selectors in the lower portion of the
screen (which functions like a simple keypad). Scanning continues in a
circular fashion through all available subsystems.

Upon exiting this menu, the instrument returns to the same menu level
(that is. Subsystem, Block, Area and Routine) that it was at before the
help function was invoked. However, the displayed menu may be differ-
ent if any scanning was performed.

■ (-)Delete — places an execution mark on the currently selected menu
name (in the upper menu area) and all items beneath it, down to the
Routine level. This inhibits the actual execution of these routines, when
(r)Run is invoked.

Visually, execution marks are displayed on the screen as an asterisk (*)
immediately to the left of the menu name (in the upper menu area). If
one, but not all, menu names in a menu are marked with an asterisk,
then the name of the menu at the next highest level (that is, from Area to
Block) is preceded by an execution mark of a minus (-).

■ (+)Add — removes the execution mark, if present, on the currently
selected menu name and all execution marks on items (that is, blocks,
areas, or routines) below the currently selected menu name (down to
the Routine level). The execution mark, if present, will change from an
asterisk (*) or minus (-) to a space.

■ (D)Debugger — normally cannot be selected and is used by qualified
service personnel only.

■ E(Exit) — terminates Extended Diagnostics and returns the instrument
to normal operating mode, but only if this selector is touched twice in
succession. The first touch causes a confirmation prompt to appear at
the top of the screen; the second touch causes the actual termination of
the Extended Diagnostics.

■ (p)Loop — toggles On and Off. When On, the selected test(s) is
executed continuously with the number of iterations displayed.

■ (t)Terse — toggles On and Off. When On, tests in the loop mode
execute at the fastest rate, but the iteration (i.e. Loop) readout is not
updated until the test is stopped (by touching the screen or a button).

■ (x)Ali — toggles On and Off. When On, all tests in the current menu are
selected to execute when started.

■ (s)Stop on Err — toggles On and Off. When On, testing stops after the
first failed test completes.

■ (r)Run/(q)Quit — starts or stops the currently selected tests.

11801C Service Manual

6-83

Diagnostic Troubieshooting

Diagnostic Menus

The upper portion of the display screen is used to display diagnostic menus.
Menus are comprised of menu items and menu fields. Menu items are rows
of items that can be selected, while menu fields are columns of status in-
formation.

There are four tiers of menus which may appear in the menu area (only one
is present at any given time), the Subsystem, Block, Area and Routine
menus. Upon entry into any menu, there is always one menu item which is
selected. Additionally, only one menu item can be selected at any given
time.

The following field descriptions apply for Subsystem, Block, Area and Rou-
tine menus.

Subsystem, Block and Area menus are divided into the following four fields:
Execution Mark, Title, Error Index Code, and Failure Count. The Routine
menu has these and three additional test result fields.

■ Execution Mark — is a one character field preceding the Title field and
succeeding the keystroke selector identification. The three values of this
field and their meanings are as follows:

‘ ’ All routines in this Subsystem, Block, or Area are available for
execution

**’ No routines in the Subsystem, Block, or Area are available for
execution

One or more routines in the Subsystem, Block, or Area are
available for execution

Refer to the Delete and Add descriptions for further information.

■ Title field — contains the name of individual hardware Subsystems,
Blocks, Areas, or Routines.

■ Error Index Code field — contains an index code. The index field may
contain one of five types of status (indicating one of four types of tests),
providing the following information:

“pass” An automatic test has executed and did not fail.

“Yxxxx” A test has failed and the failure encountered in subsys-

tem Y is xxxx. This index code contains one digit each
for Subsystem identification. Block identification. Area
identification, Routine identification, and a Test identifier
that gives some specific information about the failure.

“****” y^i-, automatic test has not yet been executed. When the

test does execute, the test will provide either pass or
Yxxxx failure status.

“ ” The test requires you to perform some type of test

set-up using the RS-232-C loopback connector. When
executed, this status provides pass or Yxxxx failure
status. To execute this test, you must select it.

6-84

Maintenance

Diagnostic Troubleshooting

“ ” (blank) This status indicates that the test requires action from
the user (such as the front panel verification tests), or
that the test is for stimulus only (such as the manual
calibration tests). This status does not provide failure
status. To execute this test, select it individually.

“????” This status indicates that an option was found that was

not present in the current instrument configuration or
that a subsystem was found that did not have a working
communication path.

■ Failure Count field — indicates the total number of routine failures (one
per routine) currently encountered in the Subsystem, Block or Area.
Thus, the Failure Count will never be more than the total number of
routines in the subsystem. If no tests have been executed or no failures
have occurred, this field is blank. Since the failure count field is an
indication of all routines that have failures, it is possible to have a failure
field count greater than the loop count (for example, there may be five
routine failures after the first loop).

A field display of 65535+ indicates that the Failure Count field has gone
beyond 65534 and that an overflow condition has occurred.

The following field descriptions apply only to Routine menus.

■ Test Results fields — contain information useful for troubleshooting.
One of the following formats is used:

■ test address, expected data, and actual data

■ expected data lower bound (minimum), expected data upper bound
(maximum) and actual data

Diagnostic Menu Hardcopy

Press the hardcopy button on the front panel to make hardcopy of the
diagnostic menu. The hardcopy is sent to a printer attached to the PRINTER
port. Screen hardcopies can also be obtained from other menus (for exam-
ple, help menus, interactive test menus, and hardware debugger menus).

After a hardcopy is output, a Form Feed is issued to the printer. If no printer
is attached or the printer can not print (for example, if the printer is off line or
if the printer is out of paper), then the following warning is shown in the
Input/Prompt area:

Hardcopy absent or off line.

The hardcopy function is unavailable for some tests requiring human inter-
action, such as touch panel interactive tests, various display tests, and
CRT/touch panel calibration patterns.

The knobs control the screen intensity during the four main diagnostics
menu levels. The TOUCH PANEL ON/OFF button enables/disables the touch
panel response to user touches.

11801C Service Manual

6-85

Diagnostic Troubieshooting

Diagnostic Terminai
Mode (RS-232-C)

The RS-232-C port drives a terminal which conforms to the ANSI 3.64 stan-
dard. In this mode, the terminal provides a screen-driven, interactive human
interface.

This mode is useful when either the display or touch panel is not functioning
properly, or when it is desired to remotely use the diagnostics with a modem
and phone link.

There are several single terminal keystroke commands which are equivalent
to front panel buttons or are terminal-only commands, all of which do not
appear on any of the display screens. The following terminal keystrokes do
appear on the screen and are shown in quotes:

■ ‘B’<baud rate> <cr> — this keystroke, followed by the baud rate and
carriage return) allows you to change the default baud rate to any one of
the allowable product baud rates (300, 1200, 9600, 19200). The default
power-up baud rate is determined from the position of two internal
jumpers located on the A14 I/O board. (The Default setting is for 9600
baud.)

■ T’ — this keystroke toggles the screen output between the current
screen display and an ANSI compatible terminal. The terminal should
initially be set in its ANSI mode.

■ ‘K’ — this keystroke toggles the screen output between the current
screen display and a Tektronix 4x05 terminal (4105, 4205).

■ ‘L’ — this keystroke toggles the screen output between the current
screen display and a Tektronix 4x07 terminal (4107, 4207).

■ ‘H’ — this keystroke produces a hardcopy of the current diagnostic
menu as described earlier.

■ ‘O’ — this keystroke disables/enables the touch panel response to the
user’s touches. It is equivalent to the TOUCH PANEL ON/OFF button.

■ ‘Q’ — this keystroke, when used in interactive test menus, stops and
starts the display information in the keypad prompt area. This keystroke
is equivalent to the ACQUISITION RUN/STOP button in those menus.

To gain access to the terminal mode diagnostics, the instrument must be in
the Extended Diagnostic mode.

To exit the terminal mode, either recycle the power, enter the (Exit) keystroke
twice to begin normal operation, or enter the appropriate ‘L’, T, or ‘K’
keystroke to transfer the screen output back to the instrument display.

6-86

Maintenance

Diagnostic Troubleshooting

System Mode (GPIB
& RS-232-C)

The Self-Test diagnostics and Extended Diagnostics are accessible using the
two commands listed in Table 6-6.

Table 6-6: System Mode Commands

Header

Argument

Notes

TEST

Set-only

TEST

[XTND]

Set-only

TEST

[MAN]

Set-only

DIAG?

Query-only

The TEST command invokes Self-Test diagnostics or Extended Diagnostic
execution. The TEST command without arguments initiates Self-Test diag-
nostics. The TEST command with argument XTND initiates Extended Diag-
nostics.

Refer to the CSA 803C and 1 1801C Digital Sampling Oscilloscope Program-
mer Manual for more information on TEST and DIAG command syntax and
usage.

The return of one of two event codes listed in Table 6-7 to the GPIB and
RS-232-C ports signals that diagnostic testing is complete.

Table 6-7: Event Code Descriptions

Event Code

Explanation

460

Self-Test or Extended Diagnostics were completed
successfully

394

Self-Test or Extended Diagnostics were completed and
failed

In either case, a GPIB/RS-232-C controller may obtain pass/fail information
through the DIAG? query.

The TEST command with argument MAN initiates the Extended Diagnostics
similarly to entering Extended Diagnostics through the front panel UTILITY
menu. The primary use of this command is to provide the remote operator a
convenient way of accessing the diagnostics through the normal RS-232-C
interface so that the operator can use the Diagnostic Terminal Mode to do
remote testing.

The TEST command with argument MAN violates normal GPIB
protocols in that, when used, the instrument becomes non-respon-
sive to further GPIB commands until normal operation is resumed.

11 801 C Service Manual

6-87

Diagnostic Troubieshooting

The DIAG? query returns pass/fail information from the most recent invoca-
tion of Self-Test diagnostics or Extended Diagnostics. Examples of possible
responses and explanations are as follows:

DIAG PASSED: NONE

This response indicates that the Self-Test diagnostics or Extended Diagnos-
tic operation did not detect any test faults.

DIAG FAILED: E1311, E1711, E1721, E1731

This response indicates that the Extended Diagnostic operation detected
test faults.

DIAG FAILED: E1311, D1211,T1431

This response indicates that the Self-Test diagnostics or Extended Diagnos-
tic operation detected test faults.

DIAG BYPASSED

This response indicates that a power-on has occurred and that Self-Test
diagnostics were bypassed through a jumper on the At 4 I/O board.

6-88

Maintenance

Diagnostic Troubleshooting

Battery Testing

The oscilloscope holds four lithium batteries to provide power when the
instrument is turned off. The following discussions provide criteria for deter-
mining if a battery has exceeded its lifetime and is thus causing incorrect
instrument operation. (A battery’s lifetime will typically exceed five years.) If
the battery voltage measures (at 20° C) equal to or greater than the voltages
given, then the circuit should operate correctly from 0° C to 50° C. (These
voltage measurements are taken with the instrument power off.)

Battery BT130 provides power for the real time clock on the At 4 I/O board. If
the clock begins to lose time rapidly when the instrument is turned off or the
diagnostics report that the Real Time Clk (E42XX) has failed, the battery
should be tested. If the battery voltage measures less than 2.7 V, then the
most likely source of the problem is the battery and you should follow the
instructions for battery replacement and disposal earlier in this section.

Battery BT150 provides power for the nonvolatile RAM (NVRAM) on the At 8
Memory board. If the diagnostics consistently report an NVRAM Battery
(E141X) failure over multiple power-ons, then the battery should be tested. If
the battery voltage measures less than 2.7 V, then the most likely source of
the problem is the battery and you should follow the instructions for battery
replacement and disposal earlier in this section.

Sockets tor devices U500 and U51 1 provide power for the NVRAM on the A5
Time Base/Controller board. If the diagnostics consistently report a Static
RAM Battery (T1331) failure over multiple power-ons, then the batteries
should be tested. If either one of the battery voltages measures less than
2.1 V as measured on pin 28 (Vcc), follow the instructions for battery re-
placement and disposal earlier in this section. (It is recommended that both
batteries be replaced at the same time.)

NOTE

Turning the instrument off while Extended Diagnostics is executing
one of the NVRAM memory tests may cause failure of the NVRAM
battery test. If the diagnostics report an NVRAM battery failure, then
exit the diagnostics. This will rewrite the confidence words into the
NVRAM. Turn the instrument off for at least one hour. Then, turn the
instrument back on. If the diagnostics still indicate an NVRAM
battery failure, then the battery should be tested.

11801C Service Manual

6-89

Diagnostic Troubieshooting

Clearing NVRAM

Before a power-up Self-Test begins — but just after the Executive processor
has run its Kernel Diagnostics — the front panel buttons are scanned by the
Executive processor. If the Executive processor senses that the WAVEFORM
and TRIGGER buttons, and only these two buttons, are pressed (i.e.,
closed) during this time, then the Executive processor resets its NVRAM to a
default state, the Teksecure Erase Memory function. This essentially de-
stroys all stored settings, stored traces, and saved trace descriptions. When
this occurs, the NVRAM is initialized by filling all but a few locations with a
default value. The following items are left intact after the NVRAM is reset:

Number of instrument power-ons (POWERON?)

Instrument power-on time (UPTIME?)

Mainframe serial number (UID? MAIN)

6-90

Maintenance

Diagnostic Troubleshooting

Field Replaceable
Unit (FRU) Guide

This section correlates Kernel Diagnostic error index codes with the compo-
nents or boards suspected of causing each error. The suspect FRU(s) for
Self-Test/Extended Diagnostics error index codes are identified by using the
built-in FRU help function, (?)Help, described under Self-Test/Extended
Diagnostics.

The FRU(s) in the Suspect board category in the following error index tables
are listed in most-to-least probable cause order. If any diagnostic errors
occur, inspect the suspect FRU for loose connections and components.
Then, repeat the Diagnostic test. If any diagnostic errors occur again, re-
place the suspect FRU(s) with a known good FRU or FRUs. Check that the
new FRU is configured exactly like the old one and that any installed firm-
ware matches the version in the old FRU.

The error index codes and tests are divided into four groups based on the
four processor subsystems: Executive, Display, Time Base, and Acquisition.
Each subsystem group has a table of kernel diagnostic error index codes. In
addition, the Executive has a table of manual test error index codes which
help extend the confidence level of instrument functionality.

If necessary, kernel error index codes for the Executive and Display subsys-
tems can be read, using a logic probe, as TTL logic levels on circuit board
pins.

11 801 C Service Manual

6-91

Diagnostic Troubieshooting

FRU Name Abbreviations

Abbreviations of FRU names are listed in Table 6-8.

Table 6-8: Board FRUs

FRU

Board

Board No

STROBEDR

M/F Strobe Driver board

(A1)

MFPOWERR

M/F Power Connect board

(A3)

REG

Regulator board

(A4)

TBC

Time Base/Controller board

(A5)

CRTSOC

CRT Socket board

(A7)

CRTDR

CRT Driver board

(A8)

TOUCH

Touch Panel assembly

(A9)

FPCTRL

Front Panel Control board

(A10)

FPBUT

Front Panel Button board

(All)

REAR

Rear Panel assembly

(A12)

MOTHER

Mother board

(A13)

Input/Output board

(A14)

MMU

Memory Management Unit board

(A15)

EXP

Executive Processor board

(A17)

MEM

Memory board

(A18)

STROBEBUF

Strobe/TDR Buffer board

(A19)

HEAD

Head Interconnect board

(A20-A23)

ACQANALOG

Acquisition Analog board

(A24/A27)

ACQMPU

Acquisition MPU board

(A25/A28)

MFACQCON

M/F Acquisition Interconnect board

(A26)

6-92

Maintenance

Diagnostic Troubleshooting

Component and Module Name Abbreviations

Abbreviations of component and module names are listed in Table 6-9.

Table 6-9; Component Module FRUs

FRU

Board

CRT

Cathode Ray Tube

Executive, Display, Time Base, or Acquisition Firmware

SDI

Serial Data Interface IC

BATTERY

Lithium Battery

Power Supply Module

NOTE

The Executive, Display, Time Base, and Acquisition firmware is
packaged in a single firmware (FW) kit; the individual parts are not
available as separate components.

11801C Service Manual

6-93

Diagnostic Troubieshooting

Executive Subsystem Error Index Codes

Error index codes for the Executive subsystem are listed in Table 6-10 along
with the suspected FRUs.

Bit patterns for these hexadecimal error index codes are displayed with the
front panel MENUS LEDs in bottom-to-top bit order. The STORE/RECALL
label represents the MSB (most significant bit) and the WAVEFORM label
represents the LSB (least significant bit). When lit, the LEDs represent a one.

For example, error index code l^ex causes the STORE/RECALL and TRIG-
GER LEDs to light.

Table 6-10: Executive Processor Kernel Error Index Codes

Error Index/^ex

Hybrid/IC FRUs

Suspect Board FRUs

IF - ID

MEM, EXP

1C - 19

MEM

18 - 16

10, EXP

EXP

EXR MEM

FPCTRL, 10, MPU

10, EXP

10 - OE

REAR, 10, MPU

MMU, EXP

EXR MEM

REAR, 10, EXR

The status LEDs (DS306 and DS307) on the A1 7 Executive Processor board
will flash while the Kernel diagnostic tests are executing. If a kernel failure is
detected, then one or both LEDs will remain on. Table 6-1 1 lists the various
LED configurations and their significance.

Reading the Executive processor subsystem error bits from the A17 Execu-
tive Processor board test points, TP201 (MSB) to TP205 (LSB), is also pos-
sible. See Figure 6-33 for the location of these test points and status LEDs.
The bits are high (-1-5 V) true.

6-94

Maintenance

Diagnostic Troubleshooting

Table 6-1 1 : Executive Processor Status LED Configuration

DS307

DS306

Significance

Power-On

OFF

Kernel Tests Executing

OFF

Kernel Tests Failed

OFF

Kernel Tests Finished

TP201 TP205

GND (MSB) (LSB) +5V

Figure 6-33: A17 Executive Processor Board Test Point and Status LED Locations

Table 6-1 2 lists the Executive processor manual tests and verification proce-
dures. If the conditions specified in the verification procedure listed are not
met, then the suspect FRUs can be found by using the (?) Help function.

These tests are performed manually and produce no error index code
displays. They are included to help you locate faulty boards that the Kernel
or Self-Test diagnostics possibly did not locate. Interconnections such as the
A13 Mother board cables and the power supply boards are not listed; how-
ever, these interconnections are considered as possible problem sources.

11801C Service Manual

6-95

Diagnostic Troubieshooting

Table 6-12: Executive Processor Manual Tests

Test Verification Procedure

Front Panel

Verify

Hard Keys This test allows you to interactively press the hard keys
to verify their operation. This test verifies the operation of
a key with both visual and audio feedback.

This test requires operator interaction and can be
executed only in the Routine pop-up menu with the All
and Loop modes set to Off. Once this test is invoked,
you can press any of the hard keys on the instrument
and verify that the corresponding image of the key on
the screen is highlighted, that the associated LED is
turned on, and that an audio click is generated.

Soft Keys This test allows you to interactively touch any of the soft
keys and verify their operation. This test verifies the op-
eration of a key with both visual and audio feedback.

This test requires operator interaction and can be
executed only in the Routine pop-up menu with the All
and Loop modes set to Off. Once this test is invoked,
you can touch any of the soft keys in the instrument and
verify that a touch box is drawn around the soft key on
the screen and that an audio click is generated.

Knobs This test allows you to turn either of the knobs and verify

their operation. This test verifies knob movement with
visual feedback.

This test requires operator interaction and can be
executed only in the Routine pop-up menu with the All
and Loop modes set to Off. Once this test is invoked,
you can turn either of the knobs on the instrument and
verify that the corresponding knob pointer on the screen
rotates and that the associated counter value changes.

Test Pattern

These tests allow you to examine and adjust the CRT
adjustments pertaining to color.

These tests require operator interaction and are only
executable in the Routine pop-up menu with the All and
Loop modes set to Off. Once one of the tests is invoked,
the operator can examine/adjust the CRT by following
the procedure outlined in the Adjustments section.

Gray Scale
Green Grid
White Grid
Red Display
Green Display
Blue Display
HV Reg Dsply

6-96

Maintenance

Diagnostic Troubleshooting

Table 6-12: Executive Processor Manual Tests (Cont.)
Test Verification Procedure

Internal I/O

Tone Gen

Ramp Tone This test verifies the capability of the instrument to gener-
ate tones through its internal speaker.

This test requires operator interaction and can be
executed only in the Routine pop-up menu with the
Loop mode set to On and the Terse and All mode set to
Off. After invoking this test, you should verify that a high-
speed clicking sound occurs.

Real Time Clk

Calibrate This test allows you to check and adjust the Real Time
Clock period.

This test requires operator interaction and can be
executed only in the Routine pop-up menu with the All
and Loop modes set to Off. Once this test is invoked,
you can examine/adjust the real time clock period follow-
ing the procedure outlined in the Real Time Clock proce-
dure in the Adjustments section.

External I/O

Printer

Pattern This test prints a set of patterns (all printable ASCII char-

acters) to help you verify the external printer interface.

This test requires operator interaction and can be
executed only in the Routine pop-up menu with the All
mode set to Off. Before executing this test, you should
connect a Centronics-compatible printer to the PRINTER
port on the rear panel of the instrument.

RS-232

Extern Loop This test verifies parts of the external RS-232-C interface.

This test requires operator interaction and can be
executed only in the Routine pop-up menu with the All
mode set to Off. Before executing this test, you should
plug an external loopback connector on the RS-232-C
connector on the rear panel of the instrument.

GPIB

Inrpt Reset
Reset Status
Data Lines
Interrupt

These tests verify the Executive processor interface to
the internal GPIB circuitry. The major external GPIB func-
tions are not tested.

This test requires operator interaction and can be
executed only in the Routine pop-up menu with the All
and Loop modes set to Off. Before executing this test,
you should unplug the GPIB connector from the instru-
ment.

Diagnostic Troubieshooting

Display Subsystem Error Index Codes

The Display subsystem error index codes and suspect FRUs are listed in
Table 6-13.

Table 6-13: Display Processor Kernel Error Index Codes

Error Index^ex

Suspect Hybrid/
1C FRUs

Suspect Board FRUs

1 - 4

MMU

5-7

MMU

The name of the first Display kernel test that fails is displayed on the screen.
The Display processor error index code is read from the A15 MMU board
test points DIAGO (LSB) to DIAG2 (MSB). The bits are high (-1-5 V) true.

The status LEDs (DS201 and DS200) on the A15 MMU board will flash while
the Kernel diagnostic tests are executing. If a kernel failure is detected, then
one or both LEDs will remain on. Table 6-14 lists the various LED configura-
tions and their significance. See Figure 6-34 for the location of these test
points and status LEDs.

Table 6-14: Display Processor Status LED Configuration

DS200

DS201

Significance

Power-On

OFF

Kernel Tests Executing

OFF

Kernel Tests Failed

OFF

Kernel Tests Finished

6-98

Maintenance

1 1 801 C Service Manual 6-99

Diagnostic Troubieshooting

Time Base Processor Error Index Codes

Error index codes for the Time Base Processor are listed in Table 6-1 5.

Table 6-15: Time Base Processor Kernel Error Index Codes

Error Index/^ex

Suspect Hybrid/
1C FRUs

Suspect Board FRUs

TBC

2-3

TBC

4-7

TBC

8 - A

TBC, MMU

TBC

TBC, MMU

The error index code bits of the first Time Base kernel test that fails are read
from the A5 Time Base/Controller board status LEDs ST4 (MSB), STS, ST2,
and ST1 (LSB). The bits are true (one) when the LED is on. Also, status
LEDs STS and ST6 indicate when the test is executing and when the test
has failed, respectively. See Figure 6-35 for the location of these status
LEDs.

The patterns from the status LEDs are applicable only when the Time Base
is executing or stopped in Kernel diagnostics.

6-100

Maintenance

Diagnostic Troubleshooting

ST1 (LSB) ST2 ST3 ST4 (MSB) STS (Test Running) STS (Test Failed)

'' V '

Status LEDs

Figure 6-35: A5 Time Base/Controller Board Status LEDs

11801C Service Manual

6-101

Diagnostic Troubieshooting

Acquisition Processor Error index Codes

Error codes for the Acquisition Processor are listed in Table 6-1 6.

The error index code bits of the first Acquisition kernel test that fails are read
from the A25/A28 Acquisition MPU board status LEDs, DS101 (MSB) and
DS100 (LSB). See Figure 6-36 for the location of these status LEDs.

The patterns from the status LEDs are applicable only when the Acquisition
is executing or stopped in Kernel diagnostics.

Table 6-16: Acquisition Processor Kernel Error Index Codes

Error Index/^ex

Suspect Hybrid/
1C FRUs

Suspect Board FRUs

ACQMPU

ACQMPU, TBC, STRO-

BEDR, MFACQCON

Status LEDs
/\

DSIOO(LSB) DS101(MSB)

Figure 6-36: A25/A28 Acquisition MPU Board Status LEDs

6-702

Maintenance

other Troubleshooting

Power Supply
Module

A4 Regulator Board

This section provides additional information and procedures for trouble-
shooting a faulty oscilloscope to the FRU level.

This procedure requires an Extended Diagnostics power supplies trouble-
shooting fixture. Refer to Table 4-2 for a complete description of the equip-
ment required.

Module Troubleshooting

If any Power Supply module problems are present, they appear when the
ON/STANDBY switch is set to ON. If the green indicator beside the ON label
fails to light, then check for the following conditions:

■ The PRINCIPAL POWER SWITCH located on the back panel is in the ON
position.

■ The line cord is connected to a functional power source with the same
output voltage as set at the LINE VOLTAGE SELECTOR on the back
panel.

■ The fuse is good. If the fuse is blown, then replace the fuse.

■ The fan is exhausting air from the instrument when the ON/STANDBY
switch is ON. A defective fan causes an over-temperature shutdown in
the power supply.

If these checks fail to correct the problem, connect the Extended Diagnos-
tics 1 1000-Series Power Supplies Test Fixture to the Power Supply module
(refer to the documentation accompanying the test fixture for troubleshoot-
ing techniques). The test fixture indicates which power supply voltage
source is at fault. To help isolate the source of the problem, set the instru-
ment’s ON/STANDBY switch to STANDBY, and disconnect the suspected
faulty power supply voltage source from the Power Supply module. Set the
ON/STANDBY switch to ON. If the test fixture does not record a fault, then
you have verified the suspected faulty power source. This procedure is only
effective for externally shorted power supplies. Once again, refer to the
documentation accompanying the test fixture for more troubleshooting
information.

This board is implicitly verified; that is, if all the other FRUs pass diagnostic
testing, then you can assume that the A4 Regulator board is operating
correctly as well.

11801C Service Manual

6-103

Other Troubleshooting

CRT, A7 CRT Socket
Board, or A8 CRT
Driver Board

A13 Mother Board

This procedure requires a test terminal and a compatible RS-232-C serial
interface cable. Refer to Table 4-2 for a complete description of the equip-
ment required.

Module Troubleshooting

If the oscilloscope powers on (the ON/STANDBY light is on), but the display
gives either scrambled information or none at all, then the CRT and A8 CRT
Driver board are suspect. The following two procedures help you determine
whether the A1 5 MMU board or one of the CRT units, (either the CRT, the A7
CRT Socket board, or the A8 CRT Driver board) is at fault.

■ With the power off (ON/STANDBY switch to STANDBY), remove the top
cover, then turn the power on. Observe the two LEDs on the A15 MMU
board and those on the A17 Executive Processor board in the card
cage. These LEDs should flicker on and off until the diagnostic tests are
complete and then all turn off. If any of these LEDs remain lit, it indicates
a problem with the board on which the LED resides. If all LEDs turn off,
then the CRT, A7 CRT Socket board, or the A8 CRT Driver board is
suspect.

■ With the power off, connect a test terminal (ANSI 3.64-compatible) to the
oscilloscope with an RS-232-C cable. Touch the screen through the full
power-on cycle to force a diagnostic error so that the instrument enters
Extended Diagnostics. On the test terminal, type T to display the EX-
TENDED DIAGNOSTICS menu on the terminal display. If the displayed
errors are only for the front panel touch screen, then the CRT, the A7
CRT Socket board or the A8 CRT Driver board is at fault. Note any other
errors and use Table 6-5, earlier in this section, to identify the suspect
subsystem.

This board is implicitly verified; that is, if all the other FRUs pass diagnostic
testing, then you can assume that the A13 Mother board is operating cor-
rectly as well.

6-104

Maintenance

Other Troubleshooting

Fuse Testing

The A14 I/O board has four fuses (see Figure 6-37). F200 supplies -l-5 V to
the A12 Rear Panel board. F800 supplies -l-5 V to the A10 Front Panel Con-
trol board and the A9 Touch Panel board. F600 supplies -i-15 V to the A14
I/O board, card cage, A10 Front Panel Control board, A9 Touch Panel board,
A1 1 Front Panel Button board, and A12 Rear Panel board (reduced to
-1-12 V). F602 supplies -15 V to the A14 I/O board, card cage, A10 Front
Panel Control board (reduced to -5 V), and A12 Rear Panel board (reduced
to -12 V).

■ F200 supplies -1-5 V to the A1 2 Rear Panel board. If diagnostics report
failure of all three ports (RS-232-C, GPIB, and PRINTER), then this fuse
is the probable suspect (assuming that the ribbon cable to the A12 Rear
Panel board is connected). When tested with a multimeter, this fuse
should measure less than 1 .5 Q.

■ F800 supplies -i-5 V to the A1 0 Front Panel Control board and the A1 1
Front Panel board. If the diagnostics report both an A9 Touch Panel
board failure and knob failures, then this fuse is one possible source of
this problem. When tested with an multimeter, this fuse should measure
less than 1 Q.

■ F600 supplies -i- 1 5 V to the A1 4 I/C board temperature sensor and tone
generator, the lights of the A1 1 Front Panel Button board, the A9 Touch
Panel board, the A12 Rear Panel board’s RS-232-C output line drivers,
the card cage, and the A17 Executive Processor board’s NVRAM. If the
NVRAM battery test and the RS-232-C External Loop Back test fail (but
the Internal Loop Back test passes) and the A1 1 Front Panel Button
board’s lights, temperature sensor, and tone generator are all off, then
this fuse is the probable suspect. When tested with an multimeter, this
fuse should measure less than 1 Q.

■ F602 supplies - 1 5 V to the A1 4 I/C board temperature sensor and tone
generator, A12 Rear Panel board’s RS-232-C output line drivers, the A9
Touch Panel board, and the card cage. If the temperature sensor, tone
generator, and RS-232-C External Loop Back test fail (but the Internal
Loop Back test passes), then this fuse is the probable suspect. When
tested with an multimeter, this fuse should measure less than 1 Q.

The A14 I/C board uses the -M5 V and -15 V supplies on board to operate
the temperature sensor and the tone generator. Cf the other card cage
boards, the A18 Memory board uses the -i-15 V supply to operate the
NVRAM circuitry. The information above and Table 6-17 will help you to
identify a failure of one of these fuses. If a test fails, then check the fuses.

WARNING

Using a replacement fuse with an incorrect current rating may
cause the ribbon cables to melt and create fire danger during a
component fault.

11 801 C Service Manual

6-105

Other Troubleshooting

See Figures 6-2 and 6-37 for the location of the line fuse and the At 4 I/O
board fuses, respectively.

When a fuse must be replaced, unsolder the fuse from the board. Be careful
not to damage the solder pads on the board. (It may be helpful to straighten
the fuse leads on the rear of the board before removing the leads from their
holes in the circuit board.) Refer to the Parts List section tor the correct value
and part number of each fuse.

Table 6-17: A14 I/O Board Fuse Failures

Fuse Executive Kernel Test Failure Self-Test/Extended Test Failure

(refer to Table 6-1 0, Executive
Subsystem Error Index Codes)

F200 lOhex (GPIB Interrupt)
open

F800 13/,ex (Front Panel Inter)

open

Note: The front panel lights do
not work, so the code must be
read from the error status test
points (TP200-TP205) on the
A17 Executive Processor board.

F600

open

Passes the Kernel diagnostic

Exec Control

E1411

tests, but the front panel lights

NVRAM

E1411

are not lit.

Battery

E1411

*Data Lines

E1421

*Addr/Data

E1431

Internal I/O

E3111

Temp Sensor

E3111

Comparator
E3111 1
*Tone Gen
*Ramp Tone (works)

Note: The front panel lights, soft
keys, and hard keys do not work.

F602 13/,ex (Front Panel Inter)

Note: The tone generator has a
very different tone.

*indicates a Manual Test forced by the operator. The test is not automatically executed by
Self-Test diagnostics.

6-106

Maintenance

Other Troubleshooting

Fuse (F200) Fuse (F600) Fuse (F602) Fuse (F800)

11801C Service Manual

6-107

Other Troubleshooting

Time Base
Calibration Errors

Table 6-18 lists the time base calibration errors that can appear on the
oscilloscope screen and the suspected faulty FRUs that cause the error. The
FRUs are listed in the order of most to least likely source of the error.

Time base calibration error messages with error codes greater than 100
have two different forms, depending on when the error occurs. If the error
occurs during power-on, then the message will say:

Time base calibration failed at power up: 2XX

where 2XX is the error code.

If the error occurs at any other time, then the message will say:

Time base calibration failed: 1XX

where 1XX is the error code.

Calibration data to enhance the time interpolator linearity is stored in NVRAM
on the Time Base/Controller board. If this NVRAM fails, a T1 331 error occurs
during power-up diagnostics. The values are written at the factory with the
GPIB command calcorrection.

CALCORRECTION<ui>:N

where <ui> = 0. . .32 and N = -128. . .-1-127

The calibration enhancement values are set at time of manufacture.
There is no query form of this command. Do NOT reset these
values. If a T1 331 failure occurs during extended power-up diag-
nostics or you suspect a time interpolator error, contact Tektronix
factory service.

A T 1 331 failure causes all N values in the 33 ui locations to be reset to zero.
The oscilloscope will still run, but with decreased accuracy in the time inter-
polator linearity. Resetting NVRAM with the Teksecure feature does not affect
the Time Base/Controller board NVRAM.

6-708

Maintenance

Other Troubleshooting

Table 6-18: Time Base Calibration Errors

Error Message

Error Code

Suspect FRU

Minor time base calibration problem:

TBC

Time base calibration failed

101 (201)

TBC

(at power-on);

102 (202)

TBC

103 (203)

TBC

111 (211)

TBC

113 (213)

TBC

115 (215)

TBC

117 (217)

TBC

121 (221)

TBC

122 (222)

TBC

123 (223)

TBC

125 (225)

TBC

126 (226)

TBC

131 (231)

TBC

STROBEBUF

STROBEDR

132 (232)

TBC

134 (234)

TBC

135 (235)

TBC

STROBEBUF

STROBEDR

136 (236)

TBC

137 (237)

TBC

138 (238)

TBC

STROBEBUF
STROBEDR, or
Sampling Head

11801C Service Manual

6-109

Other Troubleshooting

Acquisition
Caiibration Errors

When acquisition calibration errors occur, a message will appear on the
oscilloscope screen, followed by a number that indicates which Acquisition
system the error was detected in. Following this number, there will be a
string of eight, four-digit error codes that are used to identify possible faulty
FRUs. The following example shows the form that the error message will
appear:

Error detected in acquisition system AA: BBBB, CCCC, DDDD,
EEEE, FFFF, GGGG, HHHH, liil

where the A digits represent the number of the Acquisition system, and the
B, C, D, E, F, G, H, and i digits represent the four-digit error codes.

The B and i digits can be ignored. If any of the C or D digits are non-zero,
then the possible faulty FRUs, from most to least likely, are:

ACQMPU

MFACQCON

ACQANALOG

TBC

If any of the E, F, G, or H digits are non-zero, then the possible fault FRUs,
from most to least likely, are:

ACQANALOG

ACQMPU

MFACQCON

6-110

Maintenance

Options

This section contains information on instrument and power cord options
available for your 1 1 801 C digital oscilloscope.

Instrument

Options

Your instrument may be equipped with one or more options. A brief descrip-
tion of each available option is given in the following discussion. Option
information is incorporated into the appropriate sections of the manual set.
Refer to the Table of Contents for the location of option information. For
further information and prices of instrument options, see your Tektronix
Products Catalog or contact your local Tektronix service center.

Option 1 M — adds connectors for SM - 1 1 instrumentation, providing up to
1 28 additional channels for a total of 1 36 acquisition channels.

Option 1 R — adds slide rails and rackmounting hardware to convert the
benchtop instrument to a standard 19-inch rackmount version. This option
can be added at any time.

Option 1T — adds the Predefined Telecommunications Mask firmware.
This feature is standard after serial number B020000, though it still appears
as Option IT in the Identify (System Identification) pop-up menu. This
option can be added to pre-B020000 instruments.

Option A1 — replaces the standard power cord with the Universal Euro-
pean 220 V type power cord.

Option A2 — replaces the standard power cord with the United Kingdom
240 V type power cord.

Option A3 — replaces the standard power cord with the Australian 240 V
type power cord.

Option A4 — replaces the standard power cord with the North American
250 V type power cord.

Option A5 — replaces the standard power cord with the Switzerland 240 V
type power cord.

11801C Service Manual

7-1

Options

Power Cord
Information

A power cord with appropriate plug configuration is supplied with each
instrument. Table 7-1 , Power-Cord Conductor Identification, gives the color-
coding of the conductors in the power cord. If you require a power cord
other than the one supplied, refer to Figure 7-1 , Power-Cord Plug Identifica-
tion.

Table 7-1 : Power-Cord Conductor Identification

Conductor

Color

Alternate Color

Ungrounded (Line)

Brown

Black

Grounded (Neutral)

Light Blue

White

Grounded (Earth)

GreenAfellow

Green

standard*
North American
115V

Option A1
Universai Euro
230V

Option A3
Austraiian
230V

Option A4*
North American
230V

230V

Option 1A*
North American
115V/High Power

Option IB
North American
3-Phase

* Canadian Standards Association certification
inciudes these power piugs for use in the
North American power network

Figure 7-1: Power-Cord Plug Identification

7-2

Options

Electrical Parts

The modules that make up this instrument are often a combination of me-
chanical and electrical subparts. Therefore, all replaceable modules are
listed in the Parts List section. Refer to that section for part numbers when
using this manual.

11801C Service Manual

8-1

Electrical Parts

8-2

Electrical Parts List

Block Diagrams

J18 <

J35

4MHz

Data

Buffers

BADO-15

Enable

Dir

Control

Buffers

Address

Latch

J22A —

—

J22B —

J22C —

—

J22D —

—

J15

BADO-15

Rate Strobe.

Internal

Clock

Rate

Generator

Clock.

Mode.

Latch

Function

Decoder

Sense

BADO-7

Delay

DAC

Delay

DAC

±2

Fip Flop

J10

Board Select 1

Board Select 2

Unit Select

Strobe Sense 1

Strobe Sense 2

Strobe Sense 3

Strobe Sense 4

Strobe Sense 3

-•-AAAr-f-|\

-•-AAA^-f-K.

Delay 1

Delay 2

Delay 3

Delay 4

Calibrator
Out

L— Internal
Clock
Out

-To Strobe
TDR
Buffer

■\

/ J10

> J34

Figure 9-1 : 11 801 C-System Functional Block Diagram

Figure 9-2: A1 M/F Strobe Drive Board Block Diagram

11 80 1C Service Manual

9-1

To/From

Acquisition Systems
Through Strobe
Distribution

Figure 9-4: A5 Time Base/Controiier Board Biock Diagram

From A15
MMU

Figure 9-3: A4 Reguiator Board Biock Diagram

Figure 9-5: A7 CRT Socket Board Block Diagram

9-2

11 80 1C Service Manual

Printer Interface

Figure 9-6; A8 CRT Driver Board Biock Diagram

Figure 9-7: A12 Rear Panei Assembiy Biock Diagram

11 80 1C Service Manual

9 -^

PI 05 I
Executive <
Data Bus |

To/From

A17

Executive

Processor

Figure 9-8: A14 I/O Board Block Diagram

To/From

Display

Interface

Display IC

TIDEO

Bit Map
RAM

Wave-

form

Display

RAM

Figure 9-9: A15 MMU Board Block Diagram

Microprocessor

SYNC

Video

DAC

System

Reset

Executive

System

Data

Bus

Executive

System

Address

Bus

Executive

System

Control

Bus

Figure 9-10: A17 Executive Processor Board Block Diagram

9 ^

11 80 1C Service Manual

Figure 9-11: A18 Memory Board Block Diagram

11 80 1C Service Manual

Figure 9-13: A26 M/F Acquisition interconnect Board Block Diagram

9-5

9-6

To/From
Time Base
Controller

Figure 9-15: A25/A28 Acquisition MPU Board Biock Diagram

11 80 1C Service Manual

9-8

11 80 1C Service Manual

FROM JB3

A 15 MEMORY MM6T UNIT

TO JB9A

A13 STROBE/TOR BUFFER

TO J30A

A13 STROBE/TOR BUFFER

FROM JS3

A3 M/F POWER CONNECT

M/F STRD
M/F STRQ

^ g)j35

-= §) JS9A

— §) J30A

TIMEBASE

CONTRBLLER I

BOARD jg^a

A 5

4^4^ JE4D @-

<0><0> JS5A @-

J2SB (g —
JSSC @—

JESO @ —

I HYBRID ”1

I PRESC

I HYBRID I

I EXTA (§

ANTISTATIC

CONNECTION

JB0

I PRESCAL^

FRONT PANEL

TRIGGER

INPUTS

FROM J3S

A13 STROBE/TOR BUFFER

TO J33A

A13 STROBE/TDR BUFFER

TO J33B

A13 STROBE/TDR BUFFER

FROM J13

A3 M/F POWER CONNECT

FROM J34 /\

A13 STROBE/TDR BUFFER

FROM JIO /\

ASS ACQUISITION INTERCONNECT '

DELAY ASSEMBLY

12 nS DELAY I 24 nS DELAY

ji ^

CALIBRATOR

J17 ^

|-@-

I J35

J3S

J37

-§) J3B

-§) J39

-§) J33A

CALIB DRIVE SIG

-i — 4-

J17 JS7

JS7 FRONT PANEL
— @ I CALIBRATOR
OUTPUT

STROBE DRIVE
BOARD

J21C

J210

JESA @ —

JEEB —
JEEC

J2E0 @~

FRONT PANEL

INTERNAL CLOCK
OUTPUT

NO CABLE-
BOARD TO BOARD
CONNECTOR

CSA803C Detailed Block (Cabling) Diagram <C§>

11 80 1C Service Manual

9-9

9-10

11 80 1C Service Manual

POWER AND SYSTEM CONTROL

NO CABLE-
BOARD TO BOARD
CONNECTOR

11 801 C Detailed Block (Cabling) Diagram (Cont.)<(3>

11 80 1C Service Manual

9-11

9-12

11 80 1C Service Manual

Replaceable Parts

This section contains a list of the replaceable components for the 1 1 801 C.
As described below, use this list to identify and order replacement parts.

Parts Ordering
Information

Replacement parts are available from or through your local Tektronix, Inc.
service center or representative.

Changes to Tektronix instruments are sometimes made to accommodate
improved components as they become available and to give you the benefit
of the latest circuit improvements. Therefore, when ordering parts, it is
important to include the following information in your order:

■ part number

■ instrument type or model number

■ instrument serial number

■ instrument modification number, if applicable

If a part you order has been replaced with a different or improved part, your
local Tektronix service center or representative will contact you concerning
any change in the part number.

Change information, if any, is located at the rear of this manual.

Module Replacement

The 1 1 801 C is serviced by module replacement, so there are three options
you should consider:

■ Module Exchange. In some cases, you may exchange your module for
a remanufactured module. These modules cost significantly less than
new modules and meet the same factory specifications. For more in-
formation about the module exchange program, call 1 -800-TEKWIDE,
ext. BV 5799.

■ Module Repair. You may ship your module to us for repair, after which
we will return it to you.

■ New Modules. You may purchase new replacement modules in the
same way as other replacement parts.

Firmware Replacement

To replace firmware in this product, order the firmware by the part number
printed on the component label. Firmware is not listed in the replaceable
parts lists.

11801C Service Manual

10-1

Replaceable Parts

Using the
Replaceable
Parts List

The tabular information in the Replaceable Parts List is arranged for quick
retrieval. Understanding the structure and features of the list will help you
find the all the information you need for ordering replacement parts.

Item Names

In the Replaceable Parts List, an Item Name is separated from the descrip-
tion by a colon (:). Because of space limitations, an Item Name may some-
times appear as incomplete. For further Item Name identification, U.S.
Federal Cataloging Handbook H6-1 can be used where possible.

Indentation System

This parts list is indented to show the relationship between items. The
following example is of the indentation system used in the Description
column:

1 2 3 4 5 Name & Description

Assembly andlor Component

Attaching parts for Assembly and/or Component

(END ATTACHING PARTS)

Detail Part of Assembly and/or Component
Attaching parts for Detail Part

(END ATTACHING PARTS)

Parts of Detail Part

Attaching parts for Parts of Detail Part

(END ATTACHING PARTS)

Attaching parts always appear at the same indentation as the item they
mount, while the detail parts are indented to the right. Indented items are
part of, and included with, the next higher indentation. Attaching parts must
be purchased separately, unless otherwise specified.

Abbreviations

Abbreviations conform to American National Standards Institute (ANSI)
standard Y1 .1

10-2

Mechanical Parts List

Replaceable Parts

Table 10-1:

Board FRUs

FRU

Part Number

Description

670-9365-06

M/F Strobe Drive

620-0022-09

Power Supply Assembly

670-9640-00

M/F Power Connect

670-9655-01

Regulator

672-0386-00

Time Base/Controller (Standard)

672-0385-00

Time Base/Controller (w/Option 1M)

671-4471-00

Calibrator

No A#

657-0081-01

Trigger Prescaler Hybrid

672-1372-01

CRT Driver

614-0940-00

Touch Panel Assembly

A10

670-8847-01

Front Panel Control

A11

671-1130-00

Front Panel Button

A12

671-0013-00

Rear Panel

A13

671-1129-00

Mother

A14

670-8854-04

Input/Output

A15

671-1023-02

Memory Management Unit

A17

671-2888-00

Executive Processor

A18

672 -0382 -XX

Memory

A19

671-2909-00

Strobe TDR Buffer (P/0 657-)

No A#

657-0090-00

Acquisition Module

A20

670-9366-02

Head Interconnect (P/0 657-)

A21

670-9366-02

Head Interconnect (P/0 657-)

A22

670-9366-02

Head Interconnect (P/0 657-)

A23

670-9366-02

Head Interconnect (P/0 657-)

A24

670-9364-05

Acquisition Analog (P/0 657-)

A25

670-9363-01

Acquisition MPU (P/0 657-)

A26

670-9361-00

M/F Acquisition Interconnect

A27

670-9364-05

Acquisition Analog (P/0 657-)

A28

670-9363-01

Acquisition MPU (P/0 657-)

11 801 C Service Manual

10-3

Replaceable Parts

CROSS INDEX - MFR. CODE NUMBER TO MANUFACTURER

Mfr.

Code

Manufacturer

Address

City, State, Zip Code

S0482

SONY CONSUMER ELECTRONICS

TOKYO JAPAN

S3 109

FELLER

72 VERONICA AVE
UNIT 4

SUMMERSET NJ 08873

S3629

SCHURTER AG H

C/0 PANEL COMPONENTS CORP

2015 SECOND STREET

BERKELEY CA 94170

TK0435

LEWIS SCREW CO

4300 S RACINE AVE

CHICAGO IL 60609-3320

TK0488

CURRAN COIL SPRING INC

635 NW 16TH

PORTLAND OR 97209-2206

TK0588

UNIVERSAL PRECISION PRODUCTS

1775NW216TH

HILLSBORO OR 97123

TK1159

IMPROVED PRODUCTS

3400 OLYMPIC STREET

SPRINGFIELD OR 97477

TK1163

POLYCAST INC

9898 SW TIGARD ST

TIGARD OR 97223

TK1262

MURPHY ELECTRONICS INC (DIST)

TK1302

MOUNTAIN MOLDING

606 SECOND STREET

BERTHOUDCO 80513

TK1416

SHARP CORP

22-22 NAGAIKE-CHO
ABENO-KU

OSAKA JAPAN

TK1465

BEAVERTON PARTS MFG CO

1800 NW216TH AVE

HILLSBORO OR 97124-6629

TK1499

AMLAN INC

97 THORNWOOD RD

STAMFORD CT 06903-2617

TK1547

MOORE ELECTRONICS INC (DIST)

19500 SW 90TH COURT
PO BOX 1030

TUALATIN OR 97062

TK1572

RAN -ROB INC

631 85TH AVE

OAKLAND CA 94621 - 1 254

TK1617

CRAFT FACTORY PLASTICS

17145 SW ALEXANDER

ALOHA OR 97007

TK1719

NEDELCO BV (THOMAS & BETTS)

POSTBUS 6431

3002 AK ROTTERDAM THE
NETHERLANDS

TK1727

PHILIPS NEDERLAND BV
AFD ELONCO

POSTBUS 90050

5600 PB EINDHOVEN THE
NETHERLANDS

TK1869

ALPS

100 N CNTRE AVE

ROCKVILLE CENTRE NY 1 1 570

TK1905

PUGET CORP OF OREGON

7440 S W BONITA

TIGARD OR 97223

TK1916

SKS DIE CASTING CO

2200 4TH

BERKELEY CA 94710-2215

TK1943

NEILSEN MANUFACTURING INC

3501 PORTLAND ROAD NE

SALEM OR 97303

TK1967

SYNDETEK

3915 E MAIN

SPOKANE WA 99202

TK2072

PRECISION DECORATORS INC
HAWTHORNE BUSINESS CENTER

5289 NE ELAM YOUNG PARKWAY
SUITE G400

HILLSBORO OR 97124

TK2105

QUALTEK ELECTRONICS CORP
FAN-S DIV

7158 INDUSTRIAL PARK BLVD

MENTOR OH 44060

TK2122

INDUSTRIAL GASKET INC

1623 SE6THAVE

PORTLAND OR 97214-3502

TK2338

ACC MATERIALS

ED SNYDER
BLDG 38-302

BEAVERTON OR 97077

TK2435

MEC IMEX INCORPORATED

6TH FLOOR 162 CHANG AN E ROAD
SEC 2

TAIPEI, TAIWAN ROC

TK2469

UNITREK CORPORATION

3000 LEWIS & CLARK WAY
SUITE #2

VANCOUVER WA 98601

0B445

ELECTRI-CORD MFG CO INC

312 EAST MAIN ST

WESTFIELD PA 16950

0JR05

TRIQUEST CORP

3000 LEWIS AND CLARK HWY

VANCOUVER WA 98661 -2999

0J260

COMTEK MANUFACTURING OF OREGON
(METALS)

PO BOX 4200

BEAVERTON OR 97076-4200

0J9P9

GEROME MFG CO INC

PO BOX 737

NEWBERG OR 97132

10-4

Mechanical Parts List

Replaceable Parts

Mfr.

Code

0KB01

0KB05

00779

06915

11897

18677

2W944

24931

28520

29870

30010

34649

5Y400

50579

52814

53387

61058

61857

66302

71400

75915

78189

80009

83385

83486

83553

85480

93907

CROSS INDEX - MFR. CODE NUMBER TO MANUFACTURER

Manufacturer

Address

City, State, Zip Code

STAUFFER SUPPLY

810 SE SHERMAN

PORTLAND OR 97214

NORTH STAR NAMEPLATE

1281 -S NE25TH

HILLSBORO OR 971 24

AMP INC

2800 FULLING MILL
PC BOX 3608

HARRISBURG PA 17105

RICHCO PLASTIC CO

5825 N TRIPP AVE

CHICAGO IL 60646-6013

PLASTIGLIDE MFG CORP

2701 W EL SEGUNDO BLVD

HAWTHORNE CA 90250-331 8

SCAN BE MFG CO
DIV OF ZERO CORP

3445 FLETCHER AVE

EL MONTE CA91731

PAPST MECHATRONIC CORP

ACUIDNECK INDUSTRIAL PK

NEWPORT Rl 02840

SPECIALTY CONNECTOR CO INC

2100 EARLYWOOD DR
PC BOX 547

FRANKLIN IN 46131

HEYCO MOLDED PRODUCTS

750 BOULEVARD
P 0 BOX 160

KENILWORTH NJ 07033-1721

VICTOR CORP

618 MAIN STREET

WEST WARWICK Rl 02893

BICC-VERO ELECTRONICS INC

40 LINDEMAN DR

TRUMBULL CT 0661 1 -4739

INTEL CORP

SALES OFFICE /ST4-2/

3065 BOWERS AVE

SANTA CLARA CA 95051

TRIAX METAL PRODUCTS INC
DIV OF BEAVERTON PARTS MFG CO

1800 21 6TH AVE NW

HILLSBORO OR 97124-6629

SIEMENS COMPONENTS INC
OPTOELECTRONICS DIV

19000 HOMESTEAD RD

CUPERTINO CA 9501 4-071 2

TECH-ETCH INC

45ALDRIN RD

PLYMOUTH MA 02360

MINNESOTA MINING MFG CO

PC BOX 2963

AUSTIN TX 78769-2963

MATSUSHITA ELECTRIC CORP OF
AMERICA

PANASONIC INDUSTRIAL CO DIV

ONE PANASONIC WAY
PO BOX 1502

SECAUCUS NJ 07094-2917

SAN-0 INDUSTRIAL CORP

85 ORVILLE DR
PO BOX 51 1

BOHEMIA LONG ISLAND NY
11716-2501

VLSI TECHNOLOGY INC

1109 MCKAY DR

SAN JOSE CA 951 31 - 1 706

BUSSMANN

DIV OF COOPER INDUSTRIES INC

114 OLD STATE RD
PO BOX 14460

ST LOUIS MO 63178

LITTELFUSE INC
SUB TRACOR INC

800 E NORTHWEST HWY

DES PLAINES IL 6001 6-3049

ILLINOIS TOOL WORKS INC
SHAKEPROOF DIV

ST CHARLES ROAD

ELGIN IL60120

TEKTRONIX INC

14150 SW KARL BRAUN DR
PO BOX 500

BEAVERTON OR 97077-0001

MICRODOT MFG INC
GREER-CENTRAL DIV

3221 W BIG BEAVER RD

TROY Ml 48098

ELCO INDUSTRIES INC

1101 SAMUELSON RD

ROCKFORD IL61101

ASSOCIATED SPRING BARNES GROUP
INC

15001 S BROADWAY
P 0 BOX 231

GARDENA CA 90248-1 81 9

BRADY W H CO
CORP H Q

INDUSTRIAL PRODUCTS DIV

2221 W CAMDEN RD
PO BOX 2131

MILWAUKEE Wl 53209

TEXTRON INC
CAMCAR DIV

600 18TH AVE

ROCKFORD IL 61 108-5181

11 801 C Service Manual

70-5

Replaceable Parts

Fig. &

Index

No.

Tektronix
Part No.

Seriai No.
Effective Dscont

Qty

12345 Name & Description

Mfr.

Code

Mfr. Part No.

CABiNET

10-1-1

200-2191-00

CARRETAINERiPLASTIC

0JR05

ORDER BY DESC

-2

367-0248-01

HANDLE, CARRYING:16.341 L,W/CLIP

TK1465

ORDER BY DESC

-3

211-0718-00

SCREW, MACHINE:6-32 X 0.312, FLH, STL

0KB01

ORDER BY DESC

-4

212-0681-00

SCREW, MACHINES 0-32 X 0.25,PNH,STL

83486

MACHINE SCREW:

-5

426-2098-01

FRAME SECT,CAB.:LEFT SIDE

TK1465

ORDER BY DESC

-6

211-0721-00

SCREW, MACHINE:6-32 X 0.375,PNH,STL

0KB01

ORDER BY DESC

-7

101-0106-00

TRIM,DECORATIVE:LEFT SIDE, FRONT CASTING

TK1163

ORDER BY DESC

-8

426-2099-01

FRAME SECT,CAB.:RIGHT SIDE

TK1465

ORDER BY DESC

-9

348-0886-00

SHLD GSKT,ELEK:FINGER TYPE,18.310 L

TK1159

ORDER BY DESC

-10

348-0879-00

FOOT,CABINET:BOTTOM,BLUE,POLYCARB

TK1163

ORDER BY DESC

-11

348-0596-00

PAD,CAB.FOOT:0.69 X 0.255 X 0.06, PU

TK2122

348-0596-00

-12

348-0875-00

FLIPSTAND,CAB.:

TK0488

ORDER BY DESC

-13

211-0711-00

SCR,ASSEM WSHR:6-32 X 0.25,PNH,STL,T15

0KB01

ORDER BY DESC

-14

214-0603-02

PIN ASSY,SECRG:W/SPRING WASHER

0J260

ORDER BY DESC

-15

386-0227-00

STORCLRRIM CL:ACETAL

0JR05

386-0227-00

-16

386-1151-00

CLAMRRIM CLENC:SPG STL

83553

ORDER BY DESC

-17

200-3415-00

COV,CAB LIFTOFF:LOWER,AL,BLUE PAINT

80009

200341500

-18

200-3759-00

COVER, CABINETTORLIFT OFF

0J260

ORDER BY DESC

10-6

Mechanical Parts List

11 801 C Service Manual

10-7

Replaceable Parts

Fig. &

Index

Tektronix

Seriai No.

Mfr.

No.

Part No.

Effective Dscont

Qty

12345 Name & Description

Code

Mfr. Part No.

FRONT PANEL

10-2-1

614-0940-00

SUBPANEL ASSY: 1 1801 C
(SEE A9, EXCHANGE ITEM)

80009

614094000

-2

386-5806-00

FRAME, LENS:TOUCH PANEL

0JR05

ORDER BY DESC

-3

CIRCUIT BD ASSYTOUCH PANEL

(NOT REPLACEABLE, ORDER 61 4-091 6-XX)

-4

366-0600-01

PUSH BUTTON:0.269 X 0.409 ABS

TK1163

ORDER BY DESC

-5

211-0372-00

SCREW, MACHINE:4-40 X 0.31 2,PNH,STL

93907

B80- 00020 -003

-6

211-0722-00

SCREW, MACHINE:6-32 X 0.25,PNH,STL

0KB01

ORDER BY DESC

-7

386-5268-07

SUBPANEL, FRONTiFINISHED

TK1916

386-5268-07

-8

211-0721-00

SCREW, MACHINE:6-32 X 0.375,PNH,STL

0KB01

ORDER BY DESC

-9

381 -0469-00

BAR,SUPPORT:CRT

5Y400

ORDER BY DESC

-10

211-0711-00

SCR,ASSEM WSHR:6-32 X 0.25,PNH,STL,T15

0KB01

ORDER BY DESC

-11

131-1688-00

TERM, OIK DISC.:0.250 SPADE, STUD MT;MALE

00779

42822-4

-12

154-0946-00

ELECTRON TUBE:CRT, COLOR
(VI 30)

S0482

09FXES-C1

-13

210-0006-00

WASHER,LOCK:#6 INTL,0.018 THK.STL

78189

1206-00-00-0541

-14

211-0718-00

SCREW, MACHINE:6-32 X 0.312,FLH,STL

0KB01

ORDER BY DESC

-15

311-2320-00

ENCODER, DIGITAL:INCREMENTAL,50PPR

TK1869

EC24B50000FB

-16

671-1130-00

CIRCUIT BD ASSYFRONT PANEL BUTTON
(SEE A1 1 , EXCHANGE ITEM)

80009

671113000

-17

348-1075-00

SHLD GSKT,ELEK:SOLID TYPE,1 .66 L

52814

ORDER BY DESC

-18

211-0410-00

SCR,ASSEM WSHR:4-40 X 0.437,PNH,STL,T10

93907

829-07510-024

-19

260-2275-00

SWITCH, ROCKER:SPST,30MA, 12V

TK1262

ME010-D

343-0549-00

STRARTIEDOWN,E:0.098 W X 4.0 L,ZYTEL

TK1499

HW-047

-20

333-3418-00

PANEL, FRONTUPPER

TK2072

ORDER BY DESC

-21

150-0121-13

LIGHT,INDICATOR:5V,GREEN,INCANDECENT

TK1967

ORDER BY DESC

174-0616-00

CABLE ASSY,RF:50 OHM COAX,30.0 L,9-8

TK2469

ORDER BY DESC

-22

210-0586-00

NUT,PL,ASSEM WA:4-40 X 0.25, STL

TK0435

ORDER BY DESC

-23

348-1076-00

SHLD GSKT,ELEK:SOLID TYPE, 2.28 L

52814

ORDER BY DESC

-24

210-0465-00

NUT,PLAIN,HEX:0.25-32 X 0.375,BRS

0KB01

ORDER BY DESC

-25

210-0223-01

TERMINAL,LUG:0.26 ID,LOCKING,BRS TINNED

0KB01

ORDER BY DESC

315-0105-00

RES,FXD,FILM:1M OHM,5%,0.25W
(R89)

TK1727

SFR25 2322-181

-26

348-0878-00

SHLD GSKT,ELEK:SOLID TYPE,7.646 L

52814

ORDER BY DESC

-27

103-0269-00

ADAPTER,CONN:SMA TO PELTOLA

24931

39JR198-1

131-6337-00

ADAPTER,CONN:PRESCALER

24931

39AS1100

-28

333-3908-02

PANEL,FRONT:11801C,LOWER

0KB05

333-3908-01

-29

210-0895-00

WASHER,SHLDR:0.255 X 0.375 X 0.1 05 THK,NYL

TK1617

-30

136-0140-00

JACK,TIP:BANANA,CHARCOAL GRAY

TK1617

136-0140-00

-31

220-0052-00

NUT,PLAIN,HEX:M9X0.75

0KB01

ORDER BY DESC

-32

384-1682-02

SHAFT,EXTENSION:1.833 L,ALUMINUM

80009

384168202

-33

366-0600-00

PUSH BUTTON:0.269 X 0.409,ABS

TK1163

ORDER BY DESC

-34

131-4763-00

CONTACT,ELEC:GROUND,CU BE

TK2469

ORDER BY DESC

-35

211-0711-00

SCR,ASSEM WSHR:6-32 X 0.25,PNH,STL,T15

0KB01

ORDER BY DESC

10-8

Mechanical Parts List

Replaceable Parts

Fig. &

Index Tektronix Serial No. Mfr.

No. Part No. Effective Dscont Qty 12345 Name & Description Code Mfr. Part No.

Replaceable Parts

Fig. &

Index

Tektronix

Seriai No.

Mfr.

No.

Part No.

Effective Dscont

Qty

12345 Name & Description

Code

Mfr. Part No.

CHASSiS, REAR

10-3-1

200-3690-01

COVER, HIGH VOLTALUMINUM

80009

200369001

-2

211-0722-00

SCREW, MACHINE:6-32 X 0.25, PNH, STL

0KB01

ORDER BY DESC

-3

407-3438-02

BRACKET, CHASSIS:ALUMINUM

TK1943

ORDER BY DESC

-4

351 -0746-00

GUIDE,CKT BOARD:NYLON 6.803 L

0JR05

ORDER BY DESC

-5

211-0718-00

SCREW,MACHINE:6-32 X 0.312, FLH.STL

0KB01

ORDER BY DESC

-6

351 -0746-00

GUIDE,CKT BOARD:NYLON 6.803 L

0JR05

ORDER BY DESC

-7

671-0013-00

CIRCUIT BD ASSYREAR PANEL
(SEE A12, EXCHANGE ITEM)

80009

671001300

-8

211-0721-00

SCREW,MACHINE:6-32 X 0.375, PNH,STL

0KB01

ORDER BY DESC

-9

129-1085-00

SPACER, POST:0.25 L,4-40,BRS,0.25 HEX

TK0588

129-1085-00

-10

211-0410-00

SCR,ASSEM WSHR:4-40 X 0.437, PNH, STL, T10

93907

829-07510-024

-11

214-2476-01

HDW ASSY KITBAIL LOCK,ELEC CONN RCPT

53387

3475-4

-12

214-3106-00

HARDWARE KITJACK SOCKET

53387

3341 -IS

-13

211-0411-00

SCR,ASSEM WSHR:4-40 X 0.5,PNH,STL,T10

93907

ORDER BY DESC

-14

386-5369-03

PLATE,CONNECTOR:STD,ALUMINUM

TK1465

386-5369-03

-15

255-0334-00

PLASTIC CHANNEL12.75X 0.175X0.155, NYLON

11897

122-NN-2500-060

-16

211-0711-00

SCR,ASSEM WSHR:6-32 X 0.25,PNH,STL,T15

0KB01

ORDER BY DESC

-17

386-5269-02

SUBPANEL,REAR:PLATED

TK1916

ORDER BY DESC

-18

386-5283-00

SUPPORT, CHASSIS:POWER SUPPLYPOLYCARB

0JR05

ORDER BY DESC

-19

343-0081 -00

STRARRETAINING:0.125 DIA,NYLON

85480

CPNY-172BK

-20

210-0007-00

WASHER, LOCK:#8 EXT,0.02 THK.STL

0KB01

ORDER BY DESC

174-1406-00

CA ASSY,SRELEC:18,AWG,6.0 L

TK2469

ORDER BY DESC

-21

214-4082-00

PIN,GUIDE:0.850 L,METAL

TK0588

214-4082-00

-22

351 -0744-00

GUIDE,PLUG-IN:POLYAMIDE

TK1163

ORDER BY DESC

-23

610-0750-00

CHASSIS ASSY:

TK1943

ORDER BY DESC

407-4028-00

BRACKET, SUPPORT:

0J9P9

ORDER BY DESC

-24

119-4589-00

DELAY LINE,ELEC:COAXIAL,;24NS MTCHD PAIR

80009

119458900

-25

348-0532-00

GROMMET, PLASTIC:BLACK,ROUND,0.625 ID

28520

2096

-26

348-0253-00

GROMMET, PLASTIC:BLACK,OBLONG

0JR05

ORDER BY DESC

-27

210-0457-00

NUTPUASSEM WA:6-32 X 0.31 2, STL

TK0435

ORDER BY DESC

-28

343-0040-00

CLAMRCOIL:

80009

343004000

-29

211-0720-00

SCR,ASSEM WSHR:6-32 X 0.50,PNH,STL,T15

0KB01

ORDER BY DESC

-30

346-0143-00

STRARTIEDOWN,E:14.5 X 0.14, PLASTIC

TK1719

TY244M

-31

108-1462-00

COIL,RF:FXD

TK1967

ORDER BY DESC

-32

343-0085-00

CLAMRLOOP:0.312 DIA,NYLON

06915

N5-01

-33

351 -0765-00

GUIDE,CKT BOARD:NYLON

30010

29-01 24D

-34

386-1559-00

SPACER, CKT BD:0.47 H,ACETAL

80009

386155900

-35

CIRCUIT BD ASSYCRT SOCKET

(NOT REPLACEABLE, ORDER 672-1372-XX)

-36

200-3708-00

COVER,CKT BOARD:1

TK1943

ORDER BY DESC

-37

670-8847-01

CIRCUIT BD ASSYFRONT PANEL CONTROL
(SEE A10, EXCHANGE ITEM)

80009

670884701

-38

407-3840-00

BRACKET, SUPPORT:

TK1943

ORDER BY DESC

10-10

Mechanical Parts List

11 801 C Service Manual

10-11

Replaceable Parts

Fig. &

Index

Tektronix

Serial No.

Mfr.

No.

Part No.

Effective Dscont

Qty

12345 Name & Description

Code

Mfr. Part No.

CIRCUIT BOARDS

10-4-1

146-0055-00

BATTERY, DRY3.0V, 1200 MAH, LITHIUM
(BT130, BT150)

61058

BR-2/3A-E2P

-2

159-0245-00

FUSE, WIRE LEAD:1A, 125V, FAST
(F200, F600, F602, F800)

71400

TR/MCR-1

-3

156-3812-00

1C, PROCESSOR:HMOS, MICROPROCESSOR
(U830)

34649

R80286-10

156-3821-00

1C, PROCESSOR:NMOS, PERIPHERAL
(U800)

50579

SAB82258A-1N

-4

156-2622-00

IC,ASIC:HMOS,SEMI CUSTOM,STD CELL
(U330)

66302

VF4157RC CC0001

-5

671-1129-00

CIRCUIT BD ASSYMOTHER
(SEE A13, EXCHANGE ITEM)

80009

671112900

-6

211-0722-00

SCREW,MACHINE:6-32 X 0.25, PNH, STL

0KB01

ORDER BY DESC

-7

670-9655-01

CIRCUIT BD ASSYREGULATOR
(SEE A4, EXCHANGE ITEM)

80009

670965501

-8

159-0220-00

FUSE, WIRE LEAD:3A, 125V, FAST
(F430)

61857

SP5-3A

-9

211-0721-00

SCREW,MACHINE:6-32 X 0.375, PNH,STL

0KB01

ORDER BY DESC

-10

211-0408-00

SCR,ASSEM WSHR:4-40 X 0.250, PNH, STL, T10

93907

829-06815-024

-11

670-9640-00

CIRCUIT BOARD:M/F POWER CONNECT
(SEE A3, EXCHANGE ITEM)

80009

670964000

-12

211-0711-00

SCR,ASSEM WSHR:6-32 X 0.25,PNH,STL,T15

0KB01

ORDER BY DESC

-13

670-9365-06

CIRCUIT BD ASSYM/F STROBE DRIVER
(SEE A1, EXCHANGE ITEM)

80009

670936506

-14

672-0385-00

CIRCUIT BD ASSYTIMEBASE IM OPT
(SEE A5 OPT. 10, EXCHANGE ITEM)

80009

672038500

671 -4209-00

MODULAR ASSYTRIGGER PRESCALER

80009

671420901

-15

671 -4471 -00

CIRCUIT BD ASSYCALIBRATOR
(SEE No, EXCHANGE ITEM)

80009

671447100

-16

672-1372-01

CIRCUIT BD ASSYCRT DRIVER
(SEE A8, EXCHANGE ITEM)

80009

672137201

-17

159-0235-00

FUSE, WIRE LEAD:0.75A,125V,FAST
(F330)

71400

TR/MCR 3/4

-18

407-3824-00

BRACKET, SUPPORTHV XFMR,0.062 AL

5Y400

ORDER BY DESC

-19

213-0992-00

SCREW,TPG,TF:4-24 X 0.375, PNH, STL

93907

B80- 70000 -003

-20

671-1023-02

CIRCUIT BD ASSYMEMORY MANAGEMENT UNIT
(SEE A15, EXCHANGE ITEM)

80009

671102302

-21

670-8854-04

CIRCUIT BD ASSYINPUT/OUTPUT
(SEE 14, EXCHANGE ITEM)

80009

670885404

-22

671-1890-00

CIRCUIT BD ASSYMEMORY
(SEE A18, EXCHANGE ITEM)

80009

671189000

-23

671 -2888-00

CIRCUIT BD ASSYEXECUTIVE PROCESSOR

80009

671288800

(SEE Ml, EXCHANGE ITEM)

70-72

Mechanical Parts List

11 801 C Service Manual

10-13

Replaceable Parts

Fig. &
Index
No.

Tektronix
Part No.

Seriai No.
Effective Dscont

Qty

12345 Name & Description

Mfr.

Code

Mfr. Part No.

WiRE ASSEMBLiES

(SEE MAINT SECTION FOR CABLING DIAGRAM)

174-3076-00

CA ASSY,RF:COAXIAL,RFD,50 OHM, 0.10 D,6.5 L
(FROM A4J66 TO A2A2J66)

80009

174307600

174-0563-00

CA ASSYSRELEC:8,18 AWG,8.0 L
(FROM A4J64 TO A2A2J64)

TK1967

ORDER BY DESC

174-0576-00

CA ASSYSRELEC:50,28 AWG,10.3 L, RIBBON
(FROM A26J10TO A1J10)

TK1547

ORDER BY DESC

174-0577-00

CA ASSYSRELEC:1 6,28 AWG,7.5 L, RIBBON
(FROM A19J34 TO A1J34)

TK1547

ORDER BY DESC

174-0580-00

CA ASSYSRELEC:50,28 AWG,14.0 L,RIBBON
(FROM A18J83 TO A5J83)

TK1547

ORDER BY DESC

174-0609-00

CABLE ASSY,RF:50 OHM COAX,1 1 .0 L,9-0-5
(FROM A1J35 TOA5J35)

TK2469

ORDER BY DESC

174-3076-00

CA ASSYRF:COAXIAL,RFD,50 OHM,0.10 D,6.5 L
(FROM A5J32 TO A19J32)

80009

174307600

174-0623-00

CABLE ASSY,RF:50 OHM COAX,6.0 L.9-0
(FROM A1 9J30A TO A5J30B)

TK2469

ORDER BY DESC

174-0624-00

CABLE ASSY,RF:50 OHM COAX,6.0 L.9-N
(FROM A1 9J29A TO A5J29B)

TK2469

ORDER BY DESC

174-0625-00

CABLE ASSY,RF:50 OHM COAX,17.5 L,9-3
(FROM A1 9J33B TP A1 J33B)

TK2469

ORDER BY DESC

174-0751-00

CABLE ASSY,RF:50 OHM COAX,34.0 L,9-7
(FROM A1J17TO A6J17)

TK2469

ORDER BY DESC

174-0827-00

CABLE ASSY,RF:50 OHM COAX,17.5 L,9-03
(FROM A1 J33A TO A1 9J33A)

TK2469

ORDER BY DESC

174-1557-00

CAASSYSRELEC:8,22AWG, (4)12.5 L,(4)1 1.125 L
(FROM A10J74 TO ENCODERS S74 AND S75)

TK1967

ORDER BY DESC

174-1559-00

CA ASSYSRELEC:8,26 AWG,12.0 L
(FROM A7J56 TO A8J56)

TK1967

ORDER BY DESC

174-1560-00

CA ASSYSRELEC:4,26 AWG,21 .0 L, RIBBON
(FROM A4J57 TO A8J57)

TK1967

ORDER BY DESC

174-1561-00

CA ASSYSP:RIBBON,;CPR,3,26 AWG,9.0 L
(FROM A8J52 TO A15J52)

TK1967

ORDER BY DESC

174-1743-00

CAASSYPWR:DESCRETE,;PSC,4,18AWG,18.5 L
(FROM A2A2J63 TO A1 3J63A)

TK1967

ORDER BY DESC

174-1744-00

CA ASSYSRELEC:50,28 AWG
(FROM A1 0J72 TO A1 4J72)

TK1547

ORDER BY DESC

174-2030-02

CABLE ASSY,RF:50 OHM COAX,5.0 L,W/BL JKT
(FROM A5J88 TO FRONT PANEL J88)

TK2338

174-2030-02

174-3781-00

CABLE ASSY, RF:50 OHM COAX, 8.76 L,SEMI-RIGID
(FROM A4J87 TO FRONT PANEL J87)

TK2338

174-3781-00

174-1426-00

CA ASSYSRELEC:34,26 AWG,8.0 L
(FROM A5J18TOA1J18)

80009

174142600

175-9803-00

CA ASSYSP:RIBBON,;CPR,7,26 AWG, 7.5 L
(FROM A2A2J65 TO A4J65)

(FROM A7J53 TO A15J53)

(FROM A5J16TOA1J16)

TK1967

ORDER BY DESC

10-14

Mechanical Parts List

Replaceable Parts

Fig. &
Index

Tektronix

Serial No.

Mfr.

No.

Part No.

Effective Dscont Qty

12345 Name & Description

Code

Mfr. Part No.

175-9814-00

CA ASSY, SRELEC:34, 3.0 L
(FROM A1 4J77 TO A1 7J77)

TK1547

ORDER BY DESC

175-9857-00

OA ASSYSRELEC:1 1 ,18 AWG,7.25 L,RIBBON
(FROM A4J62 TO A2A2J62)

TK1967

ORDER BY DESC

11 801 C Service Manual

10-15

Replaceable Parts

Fig. &

Index

No.

Tektronix
Part No.

Seriai No.
Effective Dscont

Qty

12345 Name & Description

Mfr.

Code

Mfr. Part No.

ACQUiSiTiON MODULE

657-0090-00

MODULAR ASSYACQUISITION MODULE, 1 1 801 0
(EXCHANGE ITEM)

80009

657009000

10-5-1

670-9363-01

CIRCUIT BD ASSYACCUISITION MPU
(SEE A25. EXHANGE ITEM)

80009

670936301

-2

670-9364-05

CIRCUIT BD ASSYACCUISITION ANALOG
(SEE A24. EXHANGE ITEM)

80009

670936405

-3

670-9363-01

CIRCUIT BD ASSYACCUISITION MPU
(SEE A28, EXCHANGE ITEM)

80009

670936301

-4

670-9364-05

CIRCUIT BD ASSYACCUISITION ANALOG
(SEE A27, EXCHANGE ITEM)

80009

670936405

-5

426-2167-00

FRAME SECT, CAB. :MODULE

TK1465

426-2167-00

-6

351 -0784-00

GUIDE,CKT BD:UPPER,PR7.0 L

TK1905

GRDER BY DESC

-7

211-0392-00

SCREW,MACHINE:4-40 X 0.25,FLH,STL,T-8

93907

GRDER BY DESC

-8

426-2168-00

FRAME SECTCAB.:MODULE

TK1465

426-2168-00

-9

131-1247-00

TERM,QIK DISC.:0.187 X 0.02 BLADE,45 DEG

00779

61664-1

-10

213-0904-00

SCREW,TPG,TR:6-32 X 0.5,PNH,STL

83385

CRDER BY DESC

-11

351 -0761 -00

GUIDE,CKT BD:PLASTIC,2.5 L

18677

11633-1

-12

386-5535-00

PLATE, REARiALUMINUM

TK1943

CRDER BY DESC

-13

671 -2909-00

CIRCUIT BD ASSYSTROBE TDR BUFFER
(SEE A19, EXCHANGE ITEM)

80009

671290900

-14

211-0409-00

SCR,ASSEM WSHR:4-40 X 0.312, PNH,STL,T10

93907

829-06888-024

-15

670-9361 -00

CIRCUIT BD ASSYM/F ACOUISITION INTCON
(SEE A26, EXCHANGE ITEM)

80009

670936100

-16

407-3562-00

BRACKETCKT BD:MODULE DISCONNECTAL

TK1943

CRDER BY DESC

-17

426-2166-00

FRAME SECTCAB.:MODULE

80009

426216600

-18

386-5687-00

SUPPORTCKT BD:PLASTIC

TK1163

CRDER BY DESC

-19

211-0718-00

SCREW,MACHINE:6-32 X 0.312, FLH,STL

0KB01

CRDER BY DESC

-20

381 -0452-00

BAR,LOCKING MDL:

5Y400

CRDER BY DESC

-21

426-2165-00

FRAME SECTCAB.:MODULE

TK1465

426-2165-00

-22

384-1756-00

ROD,LOCKING:0.25,SST

TK0588

384-1756-00

-23

670-9366-02

CIRCUIT BD ASSYHEAD INTERCONNECT
(SEE A20,A21 ,A22,A23, EXCHANGE ITEMS)

80009

670936602

-24

210-0458-00

NUTPL,ASSEM WA:8-32 X 0.344,STL

0KB01

210-0458-00

-25

136-0894-00

SKT,PL-IN ELEK:3.5 X 3.5 X 1 .86,ALUMINUM

TK1916

CRDER BY DESC

-26

211-0372-00

SCREW,MACHINE:4-40 X 0.31 2,PNH,STL

93907

B80- 00020 -003

-27

348-0235-00

SHLD GSKT,ELEK: FINGER TYPE,4.734 L

TK1465

348-0235-00

-28

355-0259-00

STUD,LOCKING:0.850X 0.188 HEX,SST

TK0588

CRDER BY DESC

-29

333-3421 -00

PANEL,FRONT:

TK2072

CRDER BY DESC

-30

351 -0786-00

GUIDE,PLUG-IN:PC,3.167 L

TK1302

CRDER BY DESC

-31

386-5475-00

SUBPANEL,FR0NT:7.94 X 4.988,AL

TK1943

386-5475-00

10-16

Mechanical Parts List

11 801 C Service Manual

10-17

Replaceable Parts

Fig. &

Index Tektronix Seriai No. Mfr.

No. Part No. Effective Dscont Qty 12345 Name & Description Code Mfr. Part No.

WIRE ASSEMBLIES

(SEE MAINT SECTION FOR CABLING DIAGRAM)

174-0626-01

CABLE ASSY,RF:50 OHM COAX, 16.5 L,9-6
(FROM A1 9J1 C TO A20J1 C)

(FROM A1 9J2C TO A21 J2C)

(FROM A19J3C TO A22J3C)

(FROM A19J4C TO A23J4C)

TK2338

174-0626-01

174-0627-01

CABLE ASSY,RF:50 OHM COAX, 15.0 L,9-5
(FRO M A1 9 J 1 A TO A20 J 1 A)

(FROM A19J2A TO A21J2A)

(FAROM A1 9J3A TO A22J3A)

(FROM A1 9J4A TO A23J4A)

TK2338

174-0627-01

174-0628-01

CABLE ASSY,RF:50 OHM COAX,13.0 L,9-1
(FROM A1 8J1 B TO A20J1 B)

TK2338

174-0628-01

174-0629-01

CABLE ASSY,RF:50 OHM COAX,10.6 L,9-2
(FROM A18J1BTOA21J1B)

TK2338

174-0629-01

174-0630-01

CABLE ASSY,RF:50 OHM COAX,8.2 L.9-3
(FROM A19J3B TO A22J3B)

TK2338

174-0630-01

174-0631-01

CABLE ASSY,RF:50 OHM COAX,5.8 L.9-4
(FROM A19J4B TO A32J3B)

TK2338

174-0631-01

343-0549-00

STRARTIEDOWN,E:0.098 W X 4.0 L,ZYTEL

TK1499

HW-047

10-18

Mechanical Parts List

Replaceable Parts

Fig. &

Index

Tektronix

Serial No.

Mfr.

No.

Part No.

Effective Dscont

Qty

12345 Name & Description

Code

Mfr. Part No.

POWER SUPPLY

10-6-1

620-0022-09

POWER SUPPLY:

(SEE A2, EXCHANGE ITEM)

80009

620002209

-2

200-2222-00

GUARD, FAN:

TK2105

08213

-3

211-0744-00

SCREW, MACHINE:6-32 X 2.0,PNH,TORX,STL

TK0435

ORDER BY DESC

-4

200-2264-00

CARFUSEHOLDER:3AG FUSES

S3629

FEK031 1666

-5

159-0013-00

FUSE,CARTRIDGE:3AG,6A,250V,FAST BLOW
(F99, USED IN FUSE HOLDER)

75915

312006

159-0021-00

FUSE,CARTRIDGE:3AG,2A,250V,FAST BLOW
(F410, PART OF LINE INVERTER BOARD)

71400

AGC-2

159-0248-00

FUSE,WIRE LEAD:1.5 A

(F650, PART OF LINE INVERTER BOARD)

71400

TR/MCR-1 1/2

159-0220-00

FUSE,WIRE LEAD:3A,125V,FAST

(F740, PART OF CONTROL RECTIFIER BOARD)

61857

SP5-3A

-6

407-3362-00

BRACKET,FAN:0.050 5005 H-34

5Y400

ORDER BY DESC

-7

204-0832-00

BODY,FUSEHOLDER:3AG & 5 X 20MM FUSES

S3629

031 1673

-8

119-1725-01

FAN,TUBEAXIAL:8 14.5VDC,6W,3200RPM,106CFM

2W944

4112 KX

-9

211-0722-00

SCREW, MACHINE:6-32 X 0.25,PNH,STL

0KB01

ORDER BY DESC

11 801 C Service Manual

10-19

Replaceable Parts

Fig. &
Index
No.

Tektronix
Part No.

Seriai No.
Effective Dscont

Qty

12345 Name & Description

Mfr.

Code

Mfr. Part No.

OPTiON 1M

10-7-1

614-0940-00

SUBPANEL ASSY:
(EXCHANGE ITEM)

80009

614094000

-2

211-0721-00

SCREW, MACHINE:6-32 X 0.375, PNH, STL

0KB01

ORDER BY DESC

-3

103-0269-00

ADAPTER, CONN:SMA TO PELTOLA

24931

39JR198-1

-4

386-5472-00

PLATE,CONN MTG:ALUMINUM

TK1943

ORDER BY DESC

-5

386-5471 -00

SUBPANEUREAR:

TK1916

ORDER BY DESC

WiRE ASSEMBLiES

(SEE MAINT SECTION FOR CABLING DIAGRAM)

174-0608-00

CABLE ASSY,RF:50 OHM COAX, 167.0L, 9-2,
167.0L, 9-2,1 79.0L, 9-3, 179.0L, 9-3
(TO A1 9J23A,J30A, J33A, J33B)

(TO A5J29B.J30B)

(TO A1J33A,J33B)

TK2469

ORDER BY DESC

174-0613-00

CABLE ASSY,RF:50 OHM COAX, 7.0 L,9-N
(FROM A1 +1,+2,+3,+4 TO REAR PNL MCU TDR
DRIVE +1,+2,+3,+4)

(FROM A1 -1 ,-2,-3, -4 TO REAR PNL MCU TDR
DRIVE -1,-2, -3,-4)

(FROM A1 1 ,2,3,4 TO REAR PANEL MCU STROBE
SENSE 1,2, 3, 4)

TK2469

ORDER BY DESC

174-0618-00

CABLE ASSY,RF:50 OHM COAX, 15.0 L,9-N
(FROM A5+1 ,+2,+3,+4 TO REAR PANEL MCU
STROBE DRIVE +1,+2,+3,+4)

(FROM A5-1,-2,-3,-4 REAR PANEL MCU
STROBE DRIVE -1,-2, -3, -4)

TK2469

ORDER BY DESC

174-1093-00

CABLE ASSY,RF:50 OHM COAX,30.0 L,9-2
(FROM A1J15TOA5J15)

TK2469

ORDER BY DESC

10-20

Mechanical Parts List

Replaceable Parts

Fig. &

Index

No.

Tektronix
Part No.

Seriai No.
Effective Dscont

Qty

12345 Name & Description

Mfr.

Code

Mfr. Part No.

STANDARD ACCESSORiES

10-8-1

161-0066-00

CABLE ASSY,PWR,:3,18AWG,98 L

0B445

ECM-161 -0066-00

-2

161-0154-00

CABLE ASSY,PWR,:3,1.00MM SQ,250V,10A,2.5M
(OPTION A5 ONLY)

S3 109

12-H05WF3G 00

-3

161-0066-12

CABLE ASSY,PWR,:3,18 AWG,98 L
(OPTION A4 ONLY)

29870

ORDER BY DESC

-4

161-0066-11

CABLE ASSY,PWR,:3,1.00MM SQ,250V,10A,2.5M
(OPTION A3 ONLY)

S3 109

198-000

-5

161-0066-10

CABLE ASSY,PWR,:3,0.1MM SO, 250V, 2.5 M
(OPTION A2 ONLY)

S3 109

BS/13-H05WF3G0

-6

161-0066-09

CABLE ASSY,PWR,:3,0.75MM SO, 220V, 99.0 L
(OPTION A1 ONLY)

S3 109

86511000

174-1120-00

CA ASSY,RF:COAXIAL,;RFD,50 OHM,8.0 L

TK2469

ORDER BY DESC

174-1364-00

CABLE ASSY,RF:12.0 L,0-N

TK2469

ORDER BY DESC

070-9970-xx

MANUAL,TECH:PROGRAMMER,11801C/CSA803C

80009

0709970XX

070-9971 -XX

MANUAL,TECH:USER,11801C

80009

0709971 XX

070-9972-xx

MANUAL,TECH:SERVICE,1 1 801 C

80009

0709972XX

OPTIONAL ACCESSORIES

012-0555-00

CABLE, INTCON:CENTRONIX,3 METERS LONG

TK1416

DKIT-0034HCZZ

012-0911-00

CABLE, INTCON:MOLDED,RS232;10 FT

TK2435

ORDER BY DESC

012-0991-00

CABLE, COMPOSITE:IDC,GPIB:2 METER

00779

553577-3

012-0991-01

CABLE, GPIB:LOW EMI,1 METER

00779

553577-2

012-1220-00

CAASSYSRELEC:1 METER LONG

TK2469

ORDER BY DESC

012-1221-00

CA ASSYSRELEC:2 METER LONG

TK2469

ORDER BY DESC

200-3395-00

COVSMRLG HEAD:SNAR-IN

TK1163

ORDER BY DESC

10-22

Mechanical Parts List

Replaceable Parts

Figure 10-8: Accessories

11 801 C Service Manual

10-23

Replaceable Parts

10-24

Mechanical Parts List

Internet Archive Audio

Featured

Top

Images

Featured

Top

Software

Featured

Top

Books

Featured

Top

Video

Featured

Top

Mobile Apps

Browser Extensions

Archive-It Subscription

Save Page Now

Full text of "Tektronix Manual: 11801"

See other formats